[Docs] Improve discoverability of "Charts & Graphs" documentation

[jwflory]

Related to #72.

Summary

Make the the charts and graphs endpoint more visible and discoverable for developers using Datagrepper to build reports.

Background

Today I learned that Datagrepper has extensive functionality for building charts and graphs, which makes me feel naïve given that I have helped others frame Flock talks and reports using that data even seven years ago!

The Datagrepper docs homepage documents the search and id endpoints, but it doesn't mention anything else. It took some playing around with Sourcegraph to discover this endpoint while I was trying to walk a developer through the project and validate an idea that I had.

This is a cool feature and it is something that gives people some idea of what they can play with. Let's make it easier for people to do this!

Details

There could be a short-term and long-term fix for this:

• Short-term: Document the /charts/ endpoint on the index page of the docs.
• Long-term: Add a new page to the top-level navigation (e.g. "Endpoints"), and on this new page, link out to the Charts and Graphs page.

The long-term fix is nice because it opens the door for making other endpoints discoverable (e.g. /messagecount/) and also inviting the potential to create new endpoints for specific use cases that may not be supported by Datagrepper yet.

Outcome

New developers can better understand how to build queries that return pretty charts and graphs

[novicejava1]

HI @jwflory ,

It looks like the charts and graphs feature is available in the datagrepper/templates/index.html but it seems to be work in progress and not ready fully yet.

 <!-- <li{% if request.endpoint == 'charts' %} class="active"{% endif %}><a href="{{ url_for('charts') }}">Charts</a></li> -->

May be i can work on the charts.rst file and re-enable this endpoint from the homepage. Please suggest

[anshikavashistha]

@jwflory May I work on this issue?