chore: rename keystone to draft

Rename the module, CLI command name, and all references from
keystone/basalt to draft, and fix the stale build/README content
found along the way.

Makefile

@@ -1,4 +1,4 @@
-PKG_NAME="gitea.fernandovideira.com/FernandoJVideira/keystone"
+PKG_NAME="git.fernandovideira.com/FernandoJVideira/draft"
 
 version:
 	@go run -ldflags "-X ${PKG_NAME}/cmd.version=v1.0.0" ./main.go version
@@ -8,16 +8,16 @@ build: prepare-embed
 	@GOOS=$(GOOS) GOARCH=$(GOARCH) go build -ldflags "-X ${PKG_NAME}/cmd.version=v0.0.1" -o $(OUTPUT) ./main.go
 
 windows:
-	@$(MAKE) build GOOS=windows GOARCH=amd64 OUTPUT=keystone_windows_amd64.exe
+	@$(MAKE) build GOOS=windows GOARCH=amd64 OUTPUT=draft_windows_amd64.exe
 
 win-arm:
-	@$(MAKE) build GOOS=windows GOARCH=arm64 OUTPUT=keystone_windows_arm64.exe
+	@$(MAKE) build GOOS=windows GOARCH=arm64 OUTPUT=draft_windows_arm64.exe
 
 linux:
-	@$(MAKE) build GOOS=linux GOARCH=amd64 OUTPUT=keystone_linux_amd64
+	@$(MAKE) build GOOS=linux GOARCH=amd64 OUTPUT=draft_linux_amd64
 
 mac:
-	@$(MAKE) build GOOS=darwin GOARCH=arm64 OUTPUT=keystone_darwin_arm64
+	@$(MAKE) build GOOS=darwin GOARCH=arm64 OUTPUT=draft_darwin_arm64
 
 prepare-embed:
 	@git submodule update --init --recursive