docs: explain the options in tsconfig.lib.json

Author: haoqunjiang

tsconfig.lib.json

@@ -1,8 +1,13 @@
 {
   "compilerOptions": {
+    // Emit declaration files for the library.
     "noEmit": false,
     "declaration": true,
     "emitDeclarationOnly": true,
+
+    // Libraries generally require more strict type accuracy.
+    // For example, its types must be compatible with the Vue types.
+    // So we don't want to skip the type checking of its dependencies.
     "skipLibCheck": false
   }
 }