Fix for #210: Removed target attribute from some links.

[Nickatak]

Checklist

• [x] My branch is up-to-date with the upstream predev branch.
• [x] I have added necessary documentation (if appropriate).

Which issue does this PR fix?: Fixes issue #210 (links undesirably opening in new tab).

This PR removes the target attribute entirely for each anchor tag mentioned in issue 210 inside /oshc/main/templates/base.html. To allow for consistency, I opted to completely remove the target attribute so that it matches other in-tab-opening links on the same page. This removal has been applied to the following links:

• Request a Session (under the Session drop-down of the nav-bar)
• Contests (on the nav-bar)
• Journey (in the footer, the flower-box emblem)

Why do we need this PR?: UI/UX alteration to provide for favorable user interaction (altered links don't open in new tab when they don't need to).

Testing instructions: I have taken the following steps, and am leaving them unchecked below for you to use:

• [ ] Create a virtual environment (and activate it)
• [ ] Clone the forked repository.
• [ ] Update to predev branch if you haven't [I don't know whether git saved that or not] (git fetch https://github.com/OpenSourceHelpCommunity/OpenSourceHelpCommunity.github.io/predev)
• [ ] Install pre-commit
• [ ] collectstatic (python manage.py collectstatic)
• [ ] Run development server (python manage.py runserver)
• [ ] Click on altered links in order to verify desired functionality.

TODOs (if any): None

A picture of a cute animal (not mandatory but encouraged): Old but good:

[coveralls]

Coverage remained the same at 72.269% when pulling 4cf45634709c3efb064a414111789d7bf60f972e on Nickatak:predev into 850a09f2d46f693e723d35fa96faa323c9b9d21e on OpenSourceHelpCommunity:predev.