Added CONTRIBUTING.md #799 (#800)

* Signed off by @gaurav7019

CONTRIBUTING.md

@@ -0,0 +1,43 @@
+# Kiwix JS Contribution Guide
+
+If you have some development experience with HTML and JavaScript, we welcome Pull Requests on existing issues. Please look at this repository's Issue
+tracker, in particular those marked "good first issue". If you have found a bug, check first that we do not have an existing issue covering it, and if not, feel free to create an issue.
+
+Please follow these guidelines when contributing:
+
+- Ask to be assigned to an issue you wish to work on first (we have lots of past issues, some of which are no longer relevant or wanted);
+- We ask you only to pick issues for which you are confident that you have a solution;
+- If you are a newcomer to the repo, create a personal fork and clone it locally (for more details, see [Kiwix guidelines](https://github.com/kiwix/overview/blob/master/CONTRIBUTING.md)). Check out a new branch with a name relevant to the issue you are working on;
+- Follow the coding style of the area you are editing, including indentation, and be consistent with quotation marks and spacing;
+- Use no higher than [ECMAScript 5](https://caniuse.com/es5) - notably, do not use arrow functions or `async` functions. However, Promises *are*
+  supported via a polyfill;
+- Do not prettify code you are not working on;
+- You must test your code yourself before asking for review, like this:
+  - set up a local Web server (we recommend Node/NPM's [http-server](https://www.npmjs.com/package/http-server));
+  - serve the root directory of the repository (e.g. `http-server .`);
+  - in a browser, navigate to the URL of the main `index.html` (e.g. http://localhost:8080/www/index.html);
+  - manually test your fix in at least Firefox and Chromium (Edge or Chrome), ideally also in IE11 or in "IE Mode" in Edge;
+  - be sure to test your fix in both "JQuery" mode and "Service Worker" mode (see Configuration);
+  - run the Unit tests (see below) in at least the above browsers.
+
+If all the tests are working fine, you can finally test the extension versions, like this:
+
+  - Remove the '-WIP' from the version key from the manifest.json file present in the root of this repo;
+  - In Chromium, you can install the extension by loading the root folder with Extensions -> Load Unpacked (with Developer Mode turned ON) -> select the root folder of the repository;
+  - In Firefox, you can load an extension with Manage Your Extensions -> Debug Add-ons -> Load Temporary Add-on, and then pick any file in the repository.
+
+If your feature works and tests are passing, make a PR, describe the testing you have done, and ask for a code review.
+
+Please note that the app caches its own code so that it can run as an offline-first Progressive Web App. This can complicate development, because you
+may not see your changes, even after you refresh the browser. In Configuration, under "Expert settings", you will find a button that allows you to do
+a full app reset, which will erase the PWA. When Service Worker mode is turned on, there is also a checkbox that bypasses the App Cache. You can turn
+this on if you are frequently changing code and refreshing. Remember to turn it off for final testing. You can manually delete the App Cache in
+the browser's DevTools (see Application or Storage tabs). We also recommend you disable the browser's built-in cache, using the checkbox in the DevTools Network tab.
+
+## Unit tests
+
+Basic UI tests can be run by opening `tests/index.html` in Firefox, Edge, or Chromium/Chrome through a (local) web server.
+
+You can also run the UI tests with npm. Before running the tests, a one-time setup is needed to fetch development dependencies from the npm registry.
+Run `npm ci --ignore-scripts` to fetch the same versions as we use in CI. Then run `npm test` to run the tests against Chrome and Firefox headless
+(these browsers need to be installed in default locations).

README.md

@@ -83,11 +83,13 @@ Although the app has fast title search, it cannot yet do full text search of the
 This application is released under the GPL v3 licence. See http://www.gnu.org/licenses/ or the included LICENSE-GPLv3.txt file
 The source code can be found at https://github.com/kiwix/kiwix-js.
 
-## Unit tests
+## Contributing
 
-Unit tests can be run by opening `tests/index.html` file in Firefox, Edge, or Chromium/Chrome.
+Kiwix JS is an open-source project. We encourage individuals with experience of HTML and JavaScript development to contribute to the documentation and code in this repository.
 
-Before running the tests, a one-time set up is needed to fetch development dependencies from the npm registry. Run `npm ci --ignore-scripts` to fetch the same versions as we use in CI.
+For code contributions, read our [CONTRIBUTING](CONTRIBUTING.md) guide.
+
+To get to know the Kiwix project better, please familiarize yourself with the content on https://www.kiwix.org. There is also a Kiwix [Slack](https://join.slack.com/t/kiwixoffline/shared_invite/enQtOTUyMTg4NzMxMTM4LTU0MzYyZDliYjdmMDYzYWMzNDA0MDc4MWE5OGM0ODFhYjAxNWIxMjVjZTU4MTkyODJlZWFkMmQ2YTZkYTUzZDY) group which you can join.
 
 ## Public releases and nightly builds