feat: add ability to filter Nx projects in @commitlint/config-nx-scopes

Solves: conventional-changelog#3152

Author: jaytavares

Diff for: @commitlint/config-nx-scopes/index.js

@@ -8,7 +8,7 @@ module.exports = {
 	},
 };
 
-function getProjects(context) {
+function getProjects(context, projectType) {
 	return Promise.resolve()
 		.then(() => {
 			const ctx = context || {};
@@ -24,6 +24,9 @@ function getProjects(context) {
 		})
 		.then((projects) => {
 			return projects
+				.filter((project) =>
+					projectType ? project.projectType === projectType : true
+				)
 				.filter((project) => project.targets)
 				.map((project) => project.name)
 				.map((name) => (name.charAt(0) === '@' ? name.split('/')[1] : name));

Diff for: @commitlint/config-nx-scopes/readme.md

@@ -12,6 +12,28 @@ npm install --save-dev @commitlint/config-nx-scopes @commitlint/cli
 echo "module.exports = {extends: ['@commitlint/config-nx-scopes']};" > commitlint.config.js
 ```
 
+## Filtering projects by type
+
+You can filter projects by type by specifying the project type parameter.
+
+In your .commitlintrc.js file:
+
+```javascript
+const {
+  utils: {getProjects},
+} = require('@commitlint/config-nx-scopes');
+
+module.exports = {
+  rules: {
+    'scope-enum': async (ctx) => [
+      2,
+      'always',
+      [...(await getProjects(ctx, 'application'))], // ⬅ or 'library'
+    ],
+  },
+};
+```
+
 ## Examples
 
 ```