doc: add some documentation (#3)

Author: antoine-cottineau

README.md

@@ -10,7 +10,26 @@ This repo uses [lerna](https://lerna.js.org/) to maintain, version and publish v
 
 There is also an example app under `packages/example-app` whose goal is to demonstrate how to import and use the configuration packages.
 
-## Commands
+## Using the configurations
+
+- [Using ESLint configuration](./packages/eslint/README.md)
+
+## Installing the project
+
+- clone the project: `git clone https://github.com/bamlab/react-native-project-config`,
+- install the dependencies: `yarn install`,
+
+## Modifying the project
+
+To have a complete understanding on how to modify the project, see [Lerna's documentation](https://lerna.js.org/docs/introduction).
+
+Here are some useful commands:
+
+- creating a new package named `package-my-config`: `yarn lerna create package-my-config`,
+- rename the directory of a package: `mv package-my-config new-directory-name && yarn lerna bootstrap`,
+- run a script `do-something` that exists in at least one package: `yarn lerna run do-something` (this will try to run the script in all packages in which it is defined).
+
+## Running commands
 
 - `yarn lerna run start`: run the 'start' script in all packages (currently only present in `example-app`),
 - `yarn lerna run lint`: run the 'lint' script in all packages (currently only present in `example-app`).

packages/eslint/README.md

@@ -0,0 +1,77 @@
+# ESLint config for BAM
+
+This project is an ESLint config that gathers all the rules, plugins and parsers that should be used in any new BAM project.
+
+## How to use?
+
+In your app, run `yarn add --dev @bam.tech/eslint-config @typescript-eslint/eslint-plugin eslint`.
+
+In your `.eslintrc` config file, extend the exported configuration:
+
+```json
+// .eslintrc
+{
+  "extends": "@bam.tech/eslint-config"
+}
+```
+
+## How to customize?
+
+You can still customize your ESLint config by adding configurations, plugins and rules to your `.eslintrc` config file.
+
+## How to improve?
+
+If you find a useful rule that you feel every project at BAM should use, feel free to open a PR.
+
+Use the documentation on how to create a shareable configuration [here](https://eslint.org/docs/latest/developer-guide/shareable-configs).
+
+Here is a small summary:
+
+### Adding new rules
+
+Adding new rules is quite simple, you just have to modify `index.js` and add your rule to the `rules` object:
+
+```js
+module.exports = {
+  ...
+  rules: {
+    ...
+    "my-new-rule": "error",
+  },
+  ...
+}
+```
+
+### Extending new shareable configurations
+
+Extending new shareable configurations is quite simple, you just have to modify `index.js` and add your shareable configuration to the `extends` array (the order of configurations is important):
+
+```js
+module.exports = {
+  ...
+  extends: [
+    ...
+    "@some-scope/eslint-config",
+  ],
+  ...
+}
+```
+
+The package containing your shareable configuration should be added as a dependency by running `yarn add your-package`.
+
+### Adding a plugin
+
+Adding a plugin is quite simple, you just have to modify `index.js` and add your plugin to the `plugins` array:
+
+```js
+module.exports = {
+  ...
+  plugins: [
+    ...
+    "your-plugin",
+  ],
+  ...
+}
+```
+
+The package containing your plugin should be added as a [peer dependency](https://classic.yarnpkg.com/en/docs/dependency-types/) by running `yarn add --peer your-plugin`.