added contributing.md first revision

.github/CONTRIBUTING.md

@@ -1 +1,75 @@
-> 💡 TODO: Add contributing guide
+# Contributing to Water.css
+
+Water.css becomes better for everyone when people like you help make it better!
+
+Have any questions or concerns? Did I forget an element or selector? Does something look ugly? Feel free to submit an issue or pull request.
+
+Before contributing, please read the [code of conduct](CODE_OF_CONDUCT.md). Also you agree that your contributions will be licensed under its [MIT License](./LICENSE.md).
+
+## How to get started
+
+1. Get a copy of repository. It is recommended to fork it first and clone to your machine using `git`.
+
+2. Make sure that you have [yarn](https://yarnpkg.com) and install dependencies listed in `package.json` using it.
+
+```
+yarn
+```
+
+3. Then you can run development server with live reloading out of the box and play around with the framework.
+
+```
+yarn dev
+```
+
+So you can access the `index.html` in browser by visiting http://localhost:3000/index.html
+
+More details will be provided in command line interface.
+
+*Note.* A script that builds distribution ready files is also available but it is not the part of development workflow, it is designed to be triggered automatically while publishing a new version of a package. The script itself could be run manually:
+
+```
+yarn build
+```
+
+## How to find issues to work on
+
+If you are new to contributing open-source software, you can starty by picking any relevant issue that is tagged with `good first issue` [there](
+https://github.com/kognise/water.css/contribute).
+
+Also everyone is welcome to contribute on issues tagged with `help wanted`, you can find it filtered [here](https://github.com/kognise/water.css/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22).
+
+
+## How to make a pull request
+
+It is a few general rules of thumb about making pull requests:
+
+* Make sure that your pull request covers a small and well defined scope
+
+* Make small commits with clear and explainful messages
+
+* You need to provide a clear description about your contribution on GitHub
+
+## Directory structure
+
+```
+.
+├── dist
+├── icons
+└── src
+    ├── assets
+    ├── builds
+    └── parts
+```
+
+`dist` directory is ignored by git and it contains built assets for distribution
+
+`icons` directory contains water.css favicons used in `index.html` demo/docs file
+
+`src` directory contains all the source stylesheets groupped into folders and variables
+
+`src/assets` directory contains images used for UI elements styling
+
+`src/builds` directory contains base style files prepared for different kind of builds (i.e. light and dark themes, supporting legacy browsers, etc)
+
+`src/parts` directory contains the whole source organized in separate files by its kind like forms, links, typography