Updated Web Templates docs #7392 plus other fixes

Improved and made fixes to several other Web docs pages.
Removing old text and ref to Gettingaconnection
Fixing indentation & max line length to 80.
Fixing indentation and formatting of WebGateway json docs
Merge pull request #246 from joshmoore/rebased/develop/web_templates_7392

Web templates 7392 (rebased onto develop)
Starting 'contributing' section page edits
Deleting screenshot from images folder
Using git edits
General page tidy 1
General dev docs tidy part 2
General edits/tidying 3
General dev docs page edits
Final dev doc page tidying/edits
Fixes as per Seb's suggestions
merge develop -D org -I include -E conflict -E needs-fixes -E broken: PR 247 (Developer Docs tidy (rebased onto develop))
merge develop -D org -I include -E conflict -E needs-fixes -E broken

Repository: openmicroscopy/ome-documentation
Updating fba3536..0496ff1
Merged PRs:
  # PR 247 hflynn 'Developer Docs tidy (rebased onto develop)'

Generated by OMERO-merge-develop#163 (http://hudson.openmicroscopy.org.uk/job/OMERO-merge-develop/163/)