Add package for sharing webpack configurations for upcoming Features (#7199)

* Add package for shared webpack configurations for Lens applications, Features and libraries

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Remove duplication from gitignores

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

---------

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

packages/infrastructure/webpack/README.md

@@ -0,0 +1,76 @@
+# @k8slens/webpack
+
+This package contains webpack configurations for Lens packages.
+
+## Install
+
+```
+$ npm install @k8slens/webpack
+```
+
+## Features
+
+### Configurations
+
+### Node package
+This configuration should be used when creating package that will be executed within **Node** environment. 
+
+**webpack.config.js**
+```javascript
+module.exports = require("@k8slens/webpack").configForNode;
+```
+### React package
+This configuration should be used when creating package tha will be executed within **Browser** environment.
+
+**webpack.config.js**
+```javascript
+module.exports = require("@k8slens/webpack").configForReact;
+```
+
+### Multi export package
+
+This configuration should be used when package contains **multiple entrypoint** e.g. for different environments. You need to add `lensMultiExportConfig` to `package.json` with configuration. Note that also `exports` property needs to be set, but the correct values are generated from `lensMultiExportConfig` when using `lens-build` -script.
+
+**webpack.config.js**
+```javascript
+const packageJson = require("./package.json");
+
+module.exports = require("@k8slens/webpack").getMultiExportConfig(packageJson);
+```
+
+**package.json**
+```json
+{
+  "lensMultiExportConfig": {
+    "./main": {
+      "buildType": "node",
+      "entrypoint": "./src/main/index.ts"
+    },
+    "./renderer": {
+      "buildType": "react",
+      "entrypoint": "./src/renderer/index.ts"
+    }
+  },
+
+  "exports": {
+    "./main": {
+      "types": "./dist/main/index.d.ts",
+      "require": "./dist/main/index.js",
+      "import": "./dist/main/index.js",
+      "default": "./dist/main/index.js"
+    },
+    "./renderer": {
+      "types": "./dist/renderer/index.d.ts",
+      "require": "./dist/renderer/index.js",
+      "import": "./dist/renderer/index.js",
+      "default": "./dist/renderer/index.js"
+    }
+  }
+}
+```
+
+## Scripts
+
+1. `lens-build` which builds the packages
+2. `lens-remove-build` which removes the build directory from packages. It's useful for cleaning up.
+