JetBrains: Move marketplace link outside the plugin description area

Created by: philipp-spiess

Fixes #37823 (closed)

The JetBrains marketplace listing currently has a broken image:

The reason for this is that we add a specific section of our README to the addon description but this refers to a third party link which we don't have access to from inside JetBrains.

The easiest fix is to remove it since it is a link to the marketplace anyhow. I moved it to the title below which also makes it clearer that this link is related to our supported IDEs.

Test plan

(Readme change only though)