Simplify the runner docs and fix their outdated facts (#600)

The runner pages had drifted from the runner. They claimed Podman is unsupported, a registration retry limit of 10, a `container.env` proxy override that has no effect, and they used the deprecated `generate-config` command, while the actual instructions were buried under implementation details.

The develop and 5.x pages are rewritten from the current runner sources (`main` is `v5.2.0`). They are shorter and aimed at operators, with a new page covering what jobs get. The reference generator now documents the `config` command, and the quickstart pages in every language use the `gitea-runner` binary name.

Reviewed-on: https://gitea.com/gitea/docs/pulls/600
Reviewed-by: Lunny Xiao <[email protected]>
Co-authored-by: silverwind <[email protected]>

runner-docs/reference/cli.md

@@ -38,7 +38,7 @@ Use "gitea-runner [command] --help" for more information about a command.
 
 ## register
 
-Registers the runner against a Gitea instance and writes the registration file. Interactive unless `--no-interactive` is given; the token can also come from `--token-file` or the `GITEA_RUNNER_REGISTRATION_TOKEN` environment variable. See [Registering a runner](../registration.md).
+Registers the runner with a Gitea instance and writes the registration file. The token comes from `--token`, `--token-file` or the `GITEA_RUNNER_REGISTRATION_TOKEN` environment variable, and the command asks for the other settings unless `--no-interactive` is given. See [Registration](../registration.md).
 
 ```text
 Register a runner to the server
@@ -135,7 +135,7 @@ Global Flags:
 
 ## cache-server
 
-Runs only the cache server, so several runners can share one cache. `--dir`, `--host` and `--port` override the matching `cache.*` keys; every other setting, `cache.external_secret` included, has to come from the config file. See [Caching](../cache.md#sharing-a-cache-between-runners).
+Runs only the cache server, so several runners can share one cache. `--dir`, `--host` and `--port` override the matching `cache.*` keys. Every other setting, `cache.external_secret` included, has to come from the config file. See [Caching](../cache.md#sharing-a-cache-between-runners).
 
 ```text
 Start a cache server for the cache action
@@ -153,18 +153,137 @@ Global Flags:
   -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
 ```
 
-## generate-config
+## config
 
-Prints the commented example configuration on stdout, which is the starting point for a config file: `gitea-runner generate-config > config.yaml`.
+Writes, reads and edits config files. `config init` writes a minimal `config.yaml`, `config set`, `add` and `remove` change it in place, and `config generate` prints every option. See [Configuration](../configuration.md).
+
+```text
+Generate, read and edit config files
+
+Usage:
+  gitea-runner config [flags]
+  gitea-runner config [command]
+
+Available Commands:
+  add         Append values to a list config key
+  generate    Print the example config, which documents every option
+  get         Print the value of a config key
+  init        Write a minimal config file
+  remove      Remove values from a list config key
+  runner-file Print the registration file path used by the runner
+  set         Set the value of a config key
+
+Flags:
+  -h, --help   help for config
+
+Global Flags:
+  -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
+
+Use "gitea-runner config [command] --help" for more information about a command.
+```
+
+### config add
+
+```text
+Append values to a list config key
+
+Usage:
+  gitea-runner config add <key> <value>... [flags]
+
+Flags:
+  -h, --help   help for add
+
+Global Flags:
+  -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
+```
+
+### config generate
 
 ```text
 Print the example config, which documents every option
 
 Usage:
-  gitea-runner generate-config [flags]
+  gitea-runner config generate [flags]
 
 Flags:
-  -h, --help   help for generate-config
+  -h, --help   help for generate
+
+Global Flags:
+  -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
+```
+
+### config get
+
+```text
+Print the value of a config key
+
+Usage:
+  gitea-runner config get <key> [flags]
+
+Flags:
+  -h, --help   help for get
+
+Global Flags:
+  -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
+```
+
+### config init
+
+```text
+Write a minimal config file, leaving every option at its default.
+Without --config it writes config.yaml in the working directory.
+
+Usage:
+  gitea-runner config init [flags]
+
+Flags:
+  -f, --force   overwrite an existing config file
+  -h, --help    help for init
+
+Global Flags:
+  -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
+```
+
+### config remove
+
+```text
+Remove values from a list config key
+
+Usage:
+  gitea-runner config remove <key> <value>... [flags]
+
+Flags:
+  -h, --help   help for remove
+
+Global Flags:
+  -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
+```
+
+### config runner-file
+
+```text
+Print the registration file path used by the runner
+
+Usage:
+  gitea-runner config runner-file [flags]
+
+Flags:
+  -h, --help   help for runner-file
+
+Global Flags:
+  -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable
+```
+
+### config set
+
+```text
+Set the value of a config key
+
+Usage:
+  gitea-runner config set <key> <value>... [flags]
+
+Flags:
+  -h, --help   help for set
 
 Global Flags:
   -c, --config config   Config file path. config subcommands fall back to config.yaml in the working directory or next to the executable

runner-docs/reference/config-example.md

@@ -7,10 +7,8 @@ description: The commented example configuration of the runner, generated from t
 
 {/* Generated by update_runner_docs.sh from the gitea/runner sources, do not edit. */}
 
-This is the output of `gitea-runner generate-config`. It is safe to use unmodified,
-and it is the authoritative list of every option the runner understands. See
-[Configuration](../configuration.md) for what the options mean and how the file is
-loaded.
+Every option the runner understands, with its default, as printed by `gitea-runner config generate`.
+See [Configuration](../configuration.md) for how to write and load a config file.
 
 ```yaml
 # Every option with its default value, all commented out. Read this file, do not copy it.