[Code health] Test build on Windows with GitBash and update docs

[gis-wes]

GitBash fails to build for local or remote: (I've tried both.)

$ npm run build-all --config=local

> @ground/root@0.0.1 build-all
> npm run build --workspaces --if-present

> @ground/proto@0.0.1 build
> npm run generate:pbjs && npm run generate:pbjson && npm run generate:pbts

> @ground/proto@0.0.1 generate:pbjs
> npm run pbjs -- -t static-module -o dist/ground-protos.js

> @ground/proto@0.0.1 pbjs
> mkdir -p dist && pbjs -p src src/ground/v1beta1/*.proto -t static-module -o dist/ground-protos.js

A subdirectory or file -p already exists.
Error occurred while processing: -p.
A subdirectory or file dist already exists.
Error occurred while processing: dist.
npm error Lifecycle script `pbjs` failed with error:
npm error code 1
npm error path C:\Users\${MY_HOME}\ground\ground-platform\proto

Results in directory named "-p" in proto directory:

$ ls proto/
-p/       build.gradle  gradle/            gradlew*     package.json     src/
buf.yaml  dist/         gradle.properties  gradlew.bat  settings.gradle

This builds fine in Github Codespace. Any reason for not adding a devcontainer for local dev?