tools: Drop gomarkdoc

Motivated by reducing the set of things installed not via
RPM or Go vendoring.  I noticed this going by during a build.

For anything we want to document, there's pkg.go.dev and our
existing manual markdown.

Author: cgwalters

tools/Makefile

@@ -10,13 +10,11 @@ build:
 	mkdir -p bin
 	test -f bin/schematyper || \
 		go install github.com/idubinskiy/schematyper@latest
-	test -e bin/gomarkdoc || \
-		go install github.com/princjef/gomarkdoc/cmd/gomarkdoc@latest
 	rm -rf pkg
 
 clean:
 	rm -rfv bin
 	rm -rfv pkg
 
-install: bin/gomarkdoc bin/schematyper
-	install -v -D -t $(DESTDIR)$(PREFIX)/bin bin/{gomarkdoc,schematyper}
+install: bin/schematyper
+	install -v -D -t $(DESTDIR)$(PREFIX)/bin bin/schematyper

tools/README.md

@@ -3,5 +3,4 @@
 This directory contains Golang Tools that are needed for building/using
 `gangplank`, generating schemas, or generating Markdown documentation.
 
-- gomarkdoc
 - schematyper