Ensure Brim user can find ZQL docs

[philrz]

A user made the suggestion on Slack:

oh yeah, you guys should have a link to the query syntax somewhere in the brim app
i wasn't sure what i could type into the search box

I'd been thinking users would have come to the app after having sat through the demo video and heard about the dependency on zq/ZQL, the pointers to the repos with the language docs, etc. But the user's experience is validation that not all will be that thorough/patient (duh!)

Can we add some kind of prominent link near the search box to https://github.com/brimsec/zq/tree/master/zql/docs?

Adding also the link to query language as a new list item in the Help area is useful.

[siskojr]

I got similar queries by two more users.

Adding request to included in help section as part of @philrz description for completeness.

For reference as a familiar method for users, Wireshark provides help on the filter with a right-click action in the search pane

[philrz]

Verified in Brim commit 93ffb60. Per the attached video, the ZQL docs are now available via Help > Query Syntax Docs.

Verify.mov.zip

Thanks @r-franke!