add readme, clean up workflow names

Author: chrisfenner

.github/workflows/docker-publish.yml

@@ -51,7 +51,7 @@ jobs:
 
       # Build just the amd64 container to validate the build
       # https://github.com/docker/build-push-action
-      - name: Build and push Docker image
+      - name: Validate Docker image build
         if: github.event_name != 'release'
         id: build-only
         uses: docker/build-push-action@v3
@@ -65,7 +65,7 @@ jobs:
 
       # Build and push Docker image with Buildx
       # https://github.com/docker/build-push-action
-      - name: Build and push Docker image
+      - name: Build and publish Docker image
         if: github.event_name == 'release'
         id: build-and-push
         uses: docker/build-push-action@v3

README.md

@@ -0,0 +1,18 @@
+# TCG Pandoc Containers
+
+These Docker containers contain the dependencies needed to build TCG
+Markdown-based documents. The main anticipated consumer of these
+containers is
+[the Markdown action](https://github.com/trustedcomputinggroup/markdown),
+but anyone can download and use the containers with Docker.
+
+The interesting dependencies are:
+
+* [Pandoc](https://pandoc.org)
+* [LaTeX](https://www.latex-project.org) /
+  [TexLive](https://www.tug.org/texlive/))
+  (a dependency of Pandoc for PDF generation)
+* [Eisvogel](https://github.com/Wandmalfarbe/pandoc-latex-template)
+  (Pandoc/LaTeX template, with some TCG-specific modifications)
+* [Mermaid](https://mermaid-js.github.io/mermaid/#/) /
+  [mermaid-filter](https://github.com/raghur/mermaid-filter) (for rendering diagrams)