doc/radosgw: Cosmetic improvements and ref links in account.rst

doc/radosgw: Cosmetic improvements and ref links in account.rst

Use double backticks consistently when referring to data, commands etc.

Change links pointing to existing labels to use ref.

Use title case consistently in section titles.

Use ordered lists instead of hardcoding list numbers.

Use inline strong for emphasis instead of inline preformatted.

Change several tab to four spaces for indent.

Call it "RADOS Gateway" instead of "RadosGW".

Signed-off-by: Ville Ojamo <14869000+bluikko@users.noreply.github.com>