Add .editorconfig and .gitattributes (#186)

Add some files that belong in every repo.

- `.editorconfig` is based on `gitea` repo.
- `.gitattributes` is useful for Windows users.

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/186
Reviewed-by: Lunny Xiao <[email protected]>
Reviewed-by: delvh <[email protected]>
Co-authored-by: silverwind <[email protected]>
Co-committed-by: silverwind <[email protected]>

.gitattributes

@@ -0,0 +1 @@
+* text=auto eol=lf