chore: move strip internal option from typedoc to tsconfig

In the newest version, typedoc does no longer forward options to TypeScript. stripInternal is a TypeScript option, not a TypeDoc option. Adding it to the main file could be dangerous, though, as some types might be missing.

tsconfig.docs.json

@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.build.json",
+  "compilerOptions": {
+    "stripInternal": true
+  }
+}

typedoc.json

@@ -1,7 +1,7 @@
 {
+  "entryPoints": ["./src/index.ts"],
   "namedParamName": "props",
   "plugin": ["typedoc-plugin-param-names", "typedoc-plugin-sourcefile-url"],
-  "stripInternal": true,
-  "tsconfig": "./tsconfig.build.json",
+  "tsconfig": "./tsconfig.docs.json",
   "sourcefile-url-prefix": "https://github.com/dbartholomae/jsx-readme/blob/main/src/"
 }