fix: update readme and add missing permission

Author: qubka

.github/workflows/cmake-multiple-platform.yml

@@ -26,6 +26,7 @@ jobs:
     permissions:
       contents: write
       pull-requests: write
+      issues: write
       repository-projects: write
     runs-on: ubuntu-latest
     outputs:

README.md

@@ -66,7 +66,7 @@ plg install plugify-module-cpp
 
 2. **Write C++ Plugins**
 
-   Develop your plugins in C++ using the Plugify C++ API. Refer to the [Plugify C++ Plugin Guide](https://untrustedmodders.github.io/en/developing/plugins/first-plugin) for detailed instructions.
+   Develop your plugins in C++ using the Plugify C++ API. Refer to the [Plugify C++ Plugin Guide](https://untrustedmodders.github.io/languages/cpp/first-plugin) for detailed instructions.
 
 3. **Build and Install Plugins**