Show the API summary on the top of each Conduit API page

Summary:
Show the API summary on the top of each Conduit API page.

Before this change, the summary was only displayed from the Conduit APIs list.

Closes T15141

Test Plan:
I've opened 20 random Conduit API pages from the web
interface and I checked that now there is an amazing
"Summary" field.
I also double-checked that there were not green peppers.

Reviewers: O1 Blessed Committers, avivey

Reviewed By: O1 Blessed Committers, avivey

Subscribers: speck, tobiaswiese, Matthew, Cigaryno

Maniphest Tasks: T15141

Differential Revision: https://we.phorge.it/D25063