[Docs] - Remove OpenBB Terminal from docs page

[IgorWounds]

1. Why? (1-3 sentences or a bullet point list):

   • OpenBB Terminal is being discontinued and replaced by the OpenBB Platform and OpenBB Platform CLI.

2. What? (1-3 sentences or a bullet point list):

   • Removes the OpenBB Terminal from the docs main page.
   • Moves the OpenBB Terminal docs under the Legacy section.

3. Impact (1-2 sentences or a bullet point list):

   • Will change the look of the website.

4. Testing Done:

   • Made sure it works.

[Keyz01]

why can't i find the website

[hjoaquim]

why can't i find the website

@Keyz01 here is the URL to the website: https://openbb.co/
And the docs: https://docs.openbb.co/

The changes this PR introduces will only be reflected on the next release