jams/index.md: table, additional guides order, below → following

Update pure HTML tables to show code formatting
`…` → <code>…</code>

Admin guide, then client guide as:
* It will be the same order as the JAMS manual PDF, and
* Admin needs to be set up before clients are set up.

If printed, it may not be below, it may be on the next page.
Following includes below and next.

Change-Id: Ib41303626409cac54c963093bae18211d533cd18