docs: add contributing guide

Author: Belar

CONTRIBUTING.md

@@ -0,0 +1,59 @@
+# Contributing
+
+Everyone is welcome to contribute, in whatever form they are comfortable with. For example:
+- improve documentation,
+- test features,
+- fix bugs,
+- or add new features.
+
+## Getting Started
+
+Before diving into code or content overhaul, check if your idea isn't being work on, a quick look at issues and pull requests should do. If you are still unsure, open an issue with a brief description of what would you like to do.
+
+## Development
+
+To start working on a bug-fix, a feature, or a content update, follow these steps:
+
+1. Fork the repository.
+
+2. Link package as a dev package.
+
+To do that, when in package's directory, run `apm link --dev` in terminal. This way package will be available only in dev mode (Atom's menu bar: `View > Developer > Open in Dev Mode...`), over it's official version (if one is installed).
+
+3. Work on a problem in a dedicated branch.
+
+4. When done, submit a pull request to the main repository on GitHub.
+
+### Commit messages
+
+We are using [semantic-release], which (as part of continuous deployment) provides automatic versioning based on [conventional commits].
+
+Detailed information about message format can be found on [conventional commits] website. It's also worth checking past commits and pull requests to get an idea about how and which types are used within the repository.
+
+Each commit is checked by [commitlint], run by [Husky], and will point out any issues with a commit message - no need to worry about accidental, incorrect commits.
+
+### Debugging
+
+For general information regarding debugging in Atom, take a look at [debugging][atom-debugging] section of the Atom Flight Manual.
+
+### Language Server Protocol (LSP)
+
+Atom IDE packages revolve around [language server protocol], for which integration base is provided by [atom-languageclient].  
+
+To log communication between Atom and a language server, dedicated debugging option needs to be set in Atom's configuration, `atom.config.set('core.debugLSP', true)` - e.g. through [init file]. Log entries should be visible in the console, in Developer Tools (`ctrl+shift+i`), e.g.:
+
+```
+TypeScript (Theia) [Started] Starting Theia for some-project
+rpc.sendRequest textDocument/definition sending {textDocument: {…}, position: {…}}
+rpc.sendRequest textDocument/definition received (27ms) [{…}]
+```
+*Note: "Verbose" log level is required for some entries*
+
+[semantic-release]: https://github.com/semantic-release/semantic-release
+[conventional commits]: https://www.conventionalcommits.org/en/v1.0.0
+[commitlint]: https://commitlint.js.org
+[Husky]: https://github.com/typicode/husky
+[atom-debugging]: https://flight-manual.atom.io/hacking-atom/sections/debugging/
+[atom-languageclient]: https://github.com/atom/atom-languageclient
+[language server protocol]: https://microsoft.github.io/language-server-protocol/
+[init file]: https://flight-manual.atom.io/hacking-atom/sections/the-init-file/

README.md

@@ -14,4 +14,8 @@ Vue language support for [Atom IDE][]
 
 3. [Optional] Install [Atom IDE][] packages
 
+## Contributing
+
+Take a look at [Contributing Guide](CONTRIBUTING.md).
+
 [atom ide]: https://atom-ide-community.github.io/