(#997) Highlight Active page

[st3phhays]

Description Of Changes

The change here ensures the left side navigation
always highlights the active page. This also
makes sure that an expanded navigation item does
not collapse on reload. The trailing slash, or
lack of, has been accounted for now.

Motivation and Context

We want to ensure the left side navigation works.

Testing

• I have previewed these changes using the Docker Container or another method before submitting this pull request.

1. Pull down the pr
2. Run yarn dev, ensure the left side navigation is working properly. Try adding and removing slashes on the url to see that it just "works".
3. Close the preview terminal, and run yarn build
4. Run yarn preview
5. Try adding and removing slashes on the url to see that it just "works".

Change Types Made

• Minor documentation fix (typos etc.).
• Major documentation change (refactoring, reformatting or adding documentation to existing page).
• New documentation page added.
• The change I have made should have a video added, and I have raised an issue for this.
  • Issue #

Change Checklist

• Requires a change to menu structure (top or left-hand side)/
• Menu structure has been updated

Related Issue

Relates to #997

[gep13]

LGTM!

[gep13]

@st3phhays thanks for getting this fixed up!