Fixed broken links in documentation

[apetkau]

Description of changes

Fixed some broken links in the developer documentation. Also fixed up some info in the CHANGELOG.

Test

To test, you can build the docs as follows:

cd doc
bundle exec jekyll serve --host 0.0.0.0 --port 3000

Now you should be able to go to http://localhost:3000/irida-documentation and view the documentation.

You can remove the --host 0.0.0.0 --port 3000 and it defaults to http://localhost:4000/irida-documentation

Related issue

None.

Checklist

Things for the developer to confirm they've done before the PR should be accepted:

• CHANGELOG.md (and UPGRADING.md if necessary) updated with information for new change.
• Tests added (or description of how to test) for any new features.
• [ ] User documentation updated for UI or technical changes.