remove add-git-head-to-bikeshed-header.sh (partial revert of gpuweb#2856

)

I accidentally broke this for WGSL because the sed invocation is not the
same for both. This merges it back into the Makefiles, but still
suppresses the console output from make.

spec/Makefile

@@ -8,8 +8,10 @@ clean:
 index.pre.html: *.bs
 	DIE_ON=everything bash ../tools/invoke-bikeshed.sh index.pre.html *.bs
 
+GHC=https://github.com/gpuweb/gpuweb/blob
 index.html: index.pre.html
-	bash ../tools/add-git-head-to-bikeshed-header.sh index.pre.html > index.html
+	@echo 'Inserting source permalink: index.pre.html -> index.html'
+	@sed -e "s,gpuweb.github.io/gpuweb/</a>,gpuweb.github.io/gpuweb/</a><br><a href=\"$(GHC)/$(shell git rev-parse HEAD)/spec/index.bs\">$(GHC)/$(shell git rev-parse HEAD)/spec/index.bs</a>," <index.pre.html >index.html
 
 webgpu.idl: index.html ../tools/extract-idl-index.py
 	python3 ../tools/extract-idl-index.py index.html > webgpu.idl

wgsl/Makefile

@@ -11,8 +11,10 @@ clean:
 index.pre.html: index.bs
 	DIE_ON=everything bash ../tools/invoke-bikeshed.sh index.pre.html index.bs
 
+GHC=https://github.com/gpuweb/gpuweb/blob
 index.html: index.pre.html
-	bash ../tools/add-git-head-to-bikeshed-header.sh index.pre.html > index.html
+	@echo 'Inserting source permalink: index.pre.html -> index.html'
+	@sed -e "s,gpuweb/wgsl/</a>,gpuweb/wgsl/</a><br><a href=\"$(GHC)/$(shell git rev-parse HEAD)/wgsl/index.bs\">$(GHC)/$(shell git rev-parse HEAD)/wgsl/index.bs</a>," <index.pre.html >index.html
 
 # Extract WGSL grammar from the spec, validate it with Treesitter,
 # and use Treesitter to parse many code examples in the spec.