Add info for Viewer Docker container

.github/workflows/process-bblocks.yml

@@ -13,6 +13,7 @@ permissions:
 
 jobs:
   validate-and-process:
+    name: Validate and process
     uses: opengeospatial/bblocks-postprocess/.github/workflows/validate-and-process.yml@master
     # with:
     #   sparql_username: sparql

USAGE.md

@@ -253,7 +253,7 @@ The outputs can be generated locally by running the following:
 
 ```shell
 # Process building blocks
-docker run --pull=always --rm --workdir /workspace -v $(pwd):/workspace \
+docker run --pull=always --rm --workdir /workspace -v "$(pwd):/workspace" \
   ghcr.io/opengeospatial/bblocks-postprocess  --clean true
 # Optional - build Slate docs
 docker run --pull=always --rm \
@@ -265,9 +265,26 @@ docker run --pull=always --rm \
 **Notes**:
 
 * Docker must be installed locally for the above commands to run
+* The syntax for `-v "$(pwd):/workspace"` may vary depending on your operating system
 * Output files will be created under `build-local` (not tracked by git by default)
 * The value for `--base-url` will be used to generate the public URLs (schemas, documentation, etc.)
 
+#### Building Blocks Viewer
+
+You can also preview what the output will look like inside the Building Blocks Viewer application:
+
+```shell
+docker run --rm --pull=always -v "$(pwd):/register" -p 9090:9090 ghcr.io/ogcincubator/bblocks-viewer
+```
+
+**Notes**:
+
+* Make sure to [compile the register](#output-testing) before running the viewer (or delete `build-local`
+  altogether to view the current build inside `build`).  
+* Docker must be installed locally for the above commands to run
+* The syntax for `-v "$(pwd):/register"` may vary depending on your operating system
+* `-p 9090:9090` will publish the Viewer on port 9090 on your machine
+
 ## Tools
 
 The following tools are useful for getting each component working during development: