Update docs, file formatting and docker images (#766)

* docs: fix wrong licence link

* fix: add more formatting settings, reformat all

feat: add vscode extensions recommendations

* docs: update contributing documentation

* fix: remove unnecessary comment

it was due to broken checkout

* docs: rework installation section

it has been brought up few times, new style should be easier
to understand

* docs: update images provided by catthehacker

* docs: replace 18.04 with recent image

* fix: add final new line

.gitignore

@@ -27,5 +27,4 @@ dist/local/act
 coverage.txt
 
 .env
-#Store your GITHUB_TOKEN secret here for purposes of local testing of actions/checkout and others
-.secrets
+.secrets