docs: move doc generation scripts to subdir

Signed-off-by: David Karlsson <david.karlsson@docker.com>

docs/generate/go.mod

@@ -1,4 +1,4 @@
-module github.com/docker/cli/docs
+module github.com/docker/cli/docs/generate
 
 // dummy go.mod to avoid dealing with dependencies specific
 // to docs generation and not really part of the project.
@@ -10,4 +10,4 @@ go 1.16
 //	github.com/docker/cli-docs-tool v0.5.0
 //)
 //
-//replace github.com/docker/cli v0.0.0+incompatible => ../
+//replace github.com/docker/cli v0.0.0+incompatible => ../../

scripts/docs/generate-yaml.sh

@@ -22,11 +22,11 @@ trap clean EXIT
   # install cli-docs-tool and copy docs/tools.go in root folder
   # to be able to fetch the required depedencies
   go mod edit -modfile=vendor.mod -require=github.com/docker/cli-docs-tool@${CLI_DOCS_TOOL_VERSION}
-  cp docs/tools.go .
+  cp docs/generate/tools.go .
   # update vendor
   ./scripts/vendor update
   # build docsgen
-  go build -mod=vendor -modfile=vendor.mod -tags docsgen -o /tmp/docsgen ./docs/generate.go
+  go build -mod=vendor -modfile=vendor.mod -tags docsgen -o /tmp/docsgen ./docs/generate/generate.go
 )
 
 mkdir -p docs/yaml