perf!: make yaml dependency optional (#261)

Author: ArnaudBarre

README.md

@@ -83,6 +83,9 @@ plugins:
   postcss-plugin: {}
 ```
 
+> [!NOTE]
+> For YAML configs, you must have [yaml](https://www.npmjs.com/package/yaml) installed as a peer dependency.
+
 ### `.postcssrc.js` or `postcss.config.js`
 
 You may need some logic within your config.
@@ -100,7 +103,7 @@ In this case create JS/TS file named:
 - `postcss.config.mts`
 - `postcss.config.cts`
 
-> [!NOTE]  
+> [!NOTE]
 > For TypeScript configs, you must have [tsx](https://www.npmjs.com/package/tsx) or [jiti](https://www.npmjs.com/package/jiti) installed as a peer dependency.
 
 ```

package.json

@@ -29,8 +29,7 @@
     }
   ],
   "dependencies": {
-    "lilconfig": "^3.1.1",
-    "yaml": "^2.4.2"
+    "lilconfig": "^3.1.1"
   },
   "devDependencies": {
     "@logux/eslint-config": "^53.0.1",
@@ -59,7 +58,8 @@
   "peerDependencies": {
     "jiti": ">=1.21.0",
     "postcss": ">=8.0.9",
-    "tsx": "^4.8.1"
+    "tsx": "^4.8.1",
+    "yaml": "^2.4.2"
   },
   "peerDependenciesMeta": {
     "jiti": {
@@ -70,6 +70,9 @@
     },
     "tsx": {
       "optional": true
+    },
+    "yaml": {
+      "optional": true
     }
   },
   "c8": {