Fix broken docs links to manual build instructions (Cherry-pick of #1…

…7608) (#17610)

docs/markdown/Getting Started/getting-started/prerequisites.md

@@ -36,13 +36,13 @@ System-specific notes
 > 
 > Pants for Linux is currently distributed as a manylinux wheel. Alpine Linux is not covered by manylinux (it uses MUSL libc while manylinux requires glibc), so at present Pants will not run on Alpine Linux. 
 > 
-> If you need to run Pants on Alpine, [let us know](doc:community), so we can prioritize this work. Meanwhile, you can try [building Pants yourself](#building-pants-from-sources) on Alpine.
+> If you need to run Pants on Alpine, [let us know](doc:community), so we can prioritize this work. Meanwhile, you can try [building Pants yourself](doc:manual-installation#building-pants-from-sources) on Alpine.
 
 > 🚧 Linux on ARM is not yet supported
 > 
 > Pants for Linux is currently only distributed as an x86_64 wheel.
 > 
-> If you need to run Pants on ARM, please [upvote or comment on this issue](https://github.com/pantsbuild/pants/issues/12183) so we can prioritize this work. Meanwhile, you can try [building Pants yourself](#building-pants-from-sources) on ARM.
+> If you need to run Pants on ARM, please [upvote or comment on this issue](https://github.com/pantsbuild/pants/issues/12183) so we can prioritize this work. Meanwhile, you can try [building Pants yourself](doc:manual-installation#building-pants-from-sources) on ARM.
 
 ### macOS