Developer Docs tidy

[hflynn]

To fix typos and self-linkage etc left over from move from Trac wiki.
Also addressing https://trac.openmicroscopy.org.uk/ome/ticket/10213

[sbesson]

Can we remove the leading whitespace in this link and the following ones?

[sbesson]

Apart from minor fixes/suggestions above, I think we should adopt a standard for 2 items:

• generic method names, e.g. Class.get...(), Class.get..., Class.get*, Class.getxxx(), etc.
• non-OMERO commands, e.g. git config or :command:git config``

[hflynn]

Fixes done.
Re: standards, I prefer Class.get* although I'm happy to use xxx for replacing numbers (this is used in user docs). I'm trying to use :command: more but I don't always spot where it is applicable as yet and to be honest, I prefer the highlighting the double quotation marks give.

[sbesson]

Added a couple of extra nitpicky details that can be addressed in another PR if we want this PR to be included in the pointer of the open microscopy v.4.4.6 tag.
I will work on unifying the :command: and :omerocmd: styles in a separate PR.

[jburel]

@sbesson, @hflynn: Merging this PR. I have linked PR and the ticket i.e. https://trac.openmicroscopy.org.uk/ome/ticket/10213
Minor points noticed by @sbesson to be done in a separate PR.