Serials Docs: Improve format, fix typos, and update

This commit makes several minor changes to the Serials doc files, mostly
changes in formatting or corrections of bugs/typos. This list covers
most of the changes:

    - Add row on 'receiving' to Serials interfaces comparison table
    - Improve formatting of actionable items (using bold and arrows),
      e.g. Click on *First Menu* -> *Next Menu* -> *Last Menu*
    - Standardize formatting of form field names (using italics)
    - Improve unclear wording
    - Correct an outdated description of copy template 'status' field
      (changed before 2.3)
    - Change heading level for a subsection

Signed-off-by: Remington Steed <rjs7@calvin.edu>