Add installation docs with automation (#570)

Part of pulumi/home#3598

Generates a single index.md file with relevant content and adds
automation.

.ci-mgmt.yaml

@@ -6,6 +6,7 @@ env:
   RANCHER_URL: https://localhost # docker
 makeTemplate: bridged
 pulumiConvert: 1
+registryDocs: true
 plugins:
   - name: std
     version: "1.6.2"

Makefile

@@ -29,7 +29,7 @@ development: install_plugins provider build_sdks install_sdks
 
 build: install_plugins provider build_sdks install_sdks
 
-build_sdks: build_nodejs build_python build_dotnet build_go build_java 
+build_sdks: build_nodejs build_python build_dotnet build_go build_java build_registry_docs
 
 install_go_sdk:
 
@@ -96,6 +96,10 @@ build_python: upstream
 		cd ./bin && \
 		../venv/bin/python -m build .
 
+# Run the bridge's registry-docs command to generated the content of the installation docs/ folder at provider repo root
+build_registry_docs:
+	$(WORKING_DIR)/bin/$(TFGEN) registry-docs --out $(WORKING_DIR)/docs
+
 clean:
 	rm -rf sdk/{dotnet,nodejs,go,python}