update readme in the joss_paper branch

paper/README.md

@@ -2,17 +2,16 @@
 
 This folder contains the `paper.md`, `paper.bib` and supporting
 figures for the JOSS submission of the SPARC-X-API. Please do not add
-SPARC doc in this directory.
-
-## Using Building Actions
-
-
+SPARC doc in this directory. While most of the writings should be done
+in Markdown, please use either of the following methods for rendering
+the draft into pdf format.
 
 ## Building Locally
 
 Follow the instructions in the [JOSS
 manual](https://joss.readthedocs.io/en/latest/paper.html#docker), use
 docker (or equivalent) to build the paper locally:
+
 ```bash
 # At the paper/ subfolder of the SPARC-X-API repository
 docker run --rm \
@@ -22,3 +21,12 @@ docker run --rm \
     openjournals/inara
 ```
 This command will create the `paper.pdf` under the `paper/` subfolder.
+
+## Use Github Actions
+
+The draft pdf will be rendered after any changes are pushed the
+`paper/` under the `joss_paper` branch. Please check the [status
+page](https://github.com/alchem0x2A/SPARC-X-API/actions/workflows/joss_paper.yml)
+for the latest build action. Once the compilation is finished, the zip
+archive containing the rendered `paper.pdf` can be downloaded via the
+link in the "Artifacts" section of the action status.