feat(tgnms): add file structure to top-level README

Summary: Briefly describe important directories in the top-level README.md

Reviewed By: aclave1

Differential Revision: D38083734

fbshipit-source-id: 5b4bcc3861eb8cd07fa9f9ed8c4a091f73b709bb

.github/workflows/main.yml

@@ -89,7 +89,7 @@ jobs:
  run: |
  python jenkins_scripts/registry.py build scan_service --dir scan_service --github-user "$GITHUB_USER" --branch "$GIT_BRANCH" --registry "$DOCKER_REGISTRY"
  python jenkins_scripts/registry.py push scan_service --username "$DOCKER_USERNAME" --github-user "$GITHUB_USER" --registry "$DOCKER_REGISTRY"
- - name: Network Health Service
+ - name: MSA Network Health Service
  run: |
  python jenkins_scripts/registry.py build network_health_service --dir network_health_service --github-user "$GITHUB_USER" --branch "$GIT_BRANCH" --registry "$DOCKER_REGISTRY"
  python jenkins_scripts/registry.py push network_health_service --username "$DOCKER_USERNAME" --github-user "$GITHUB_USER" --registry "$DOCKER_REGISTRY"
@@ -101,7 +101,7 @@ jobs:
  run: |
  python jenkins_scripts/registry.py build network_test --dir network_test --github-user "$GITHUB_USER" --branch "$GIT_BRANCH" --registry "$DOCKER_REGISTRY"
  python jenkins_scripts/registry.py push network_test --username "$DOCKER_USERNAME" --github-user "$GITHUB_USER" --registry "$DOCKER_REGISTRY"
- - name: MSA Default Router Service
+ - name: MSA Default Routes Service
  run: |
  python jenkins_scripts/registry.py build default_routes_service --dir default_routes_service --github-user "$GITHUB_USER" --branch "$GIT_BRANCH" --registry "$DOCKER_REGISTRY"
  python jenkins_scripts/registry.py push default_routes_service --username "$DOCKER_USERNAME" --github-user "$GITHUB_USER" --registry "$DOCKER_REGISTRY"

README.md

@@ -88,11 +88,19 @@ nms install -f config.yml
 ```
 
 ## Developer Guide
-[See here](tgnms/fbcnms-projects/tgnms/README.md).
-
-Additional documentation for the TGNMS can be found
+Additional NMS documentation can be found
 [here](http://terragraph.github.io/tgnms).
 
+Repository file structure (non-exhaustive list):
+* **nms_stack** - NMS installer for the entire Terragraph cloud suite
+* **tgnms** - NMS UI ([see here](tgnms/fbcnms-projects/tgnms/README.md))
+* **docs** - NMS UI documentation
+* **tglib** - Python framework for building applications within the Terragraph
+ Microservice Architecture (MSA)
+* **docker** - Build scripts for C++ backend services including Query Service
+ and UDP Pinger
+* **if** - Thrift interface definitions shared across many services
+
 ## Overall Architecture
 ![image](readme_images/ArchitectureOverview.png)