[CI:DOCS] Add local html build info to docs/README.md

Rename Readme.md to README.md in the docs directory.   Add
the local build process per @Luap99 in #9856 for the man pages
to preview any changes that are made.

Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/docs/README.md b/docs/README.md
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+# Podman Documentation
+
+The online man pages and other documents regarding Podman can be found at
+[Read The Docs](https://podman.readthedocs.io).  The man pages
+can be found under the [Commands](https://podman.readthedocs.io/en/latest/Commands.html)
+link on that page.
+
+# Build the Docs
+
+## Directory Structure
+
+|                                      | Directory                   |
+| ------------------------------------ | --------------------------- |
+| Markdown source for man pages        | docs/source/markdown/       |
+| man pages aliases as .so files       | docs/source/markdown/links/ |
+| restructured text for readthedocs.io | docs/rst/                   |
+| target for output                    | docs/build                  |
+| man pages                            | docs/build/man              |
+| remote linux man pages               | docs/build/remote/linux     |
+| remote darwin man pages              | docs/build/remote/darwin    |
+| remote windows html pages            | docs/build/remote/windows   |
+
+## Support files
+
+| | |
+| ------------------------------------ | --------------------------- |
+| docs/remote-docs.sh | Read the docs/source/markdown files and format for each platform |
+| docs/links-to-html.lua | pandoc filter to do aliases for html files |
+
+## API Reference
+
+The [latest online documentation](http://docs.podman.io/en/latest/_static/api.html) is
+automatically generated by two cooperating automation systems based on committed upstream
+source code.  Firstly, [the Cirrus-CI docs task](../contrib/cirrus/README.md#docs-task) builds
+`pkg/api/swagger.yaml` and uploads it to a public-facing location (Google Storage Bucket -
+an online service for storing unstructured data).  Second, [Read The Docs](readthedocs.com)
+reacts to the github.com repository change, building the content for the [libpod documentation
+site](https://podman.readthedocs.io/).  This site includes for the API section,
+some javascript which consumes the uploaded `swagger.yaml` file directly from the Google
+Storage Bucket.
+
+Since there are multiple systems and local cache is involved, it's possible that updates to
+documentation (especially the swagger/API docs) will lag by 10-or-so minutes.  However,
+because the client (i.e. your web browser) is fetching content from multiple locations that
+do not share a common domain, accessing the API section may show a stack-trace similar to
+the following:
+
+![JavaScript Stack Trace Image](../contrib/cirrus/swagger_stack_trace.png)
+
+If reloading the page, or clearing your local cache does not fix the problem, it is
+likely caused by broken metadata needed to protect clients from cross-site-scripting
+style attacks.  Please [notify a maintainer](https://github.com/containers/podman#communications)
+so they may investigate how/why the `swagger.yaml` file's CORS-metadata is
+incorrect, or the file isn't accessible for some other reason.
+
+## Local Testing
+
+Assuming that you have the [dependencies](https://podman.io/getting-started/installation#build-and-run-dependencies)
+installed, then also install (showing Fedora in the example):
+
+```
+# dnf install python3-sphinx python3-recommonmark
+# pip install sphinx-markdown-tables
+```
+After that completes, cd to the `docs` directory in your Podman sandbox and then do `make html`.
+
+You can then preview the html files in `docs/build/html` with:
+```
+python -m http.server 8000 --directory build/html
+```