docs: keep Installation section as single Installation Guide link

Remove Kernel Flasher and magiskboot direct links from README and
features Installation lines - Installation Guide is the single entry point.

README.md

@@ -50,7 +50,7 @@ Full documentation: [docs/features.md](docs/features.md)
 
 ## Installation
 
-See **[Installation Guide](docs/installation.md)** - [Kernel Flasher](docs/kernelflasher.md) · [Patch boot.img with magiskboot](docs/magiskboot.md).
+See **[Installation Guide](docs/installation.md)**.
 
 ---
 

docs/features.md

@@ -63,6 +63,6 @@ Per-feature documentation for the GKI2 kernels built from this repository.
 
 ---
 
-**Installation** - see [Installation Guide](installation.md) ([Kernel Flasher](kernelflasher.md) · [Patch boot.img with magiskboot](magiskboot.md)).
+**Installation** - see [Installation Guide](installation.md).
 
 **Release Notes** - for build-specific version/commit info, see the [release workflow](https://github.com/WildKernels/GKI_KernelSU_SUSFS/actions/workflows/main.yml) or the releases page.