v1.6.0: Generate a lookup table for Gecko categorical histograms (#104)

* Generate a lookup table for Gecko categorical histograms

This adds a function to look up labeled counters that
will represent Gecko categorical histograms.

* Add an entry to HISTORY.rst

v1.5.1

Remove warnings in the generated Kotlin template (#97)

v1.5.0: Add support for Gecko scalars (#96)

* Rename the Gecko output file for Kotlin

This additionally changes the function to get
the Glean type from the Gecko histogram name
from `get` to `getHistogram`.

* Move scalars out of the histograms mapping

* Bonus: fix import ordering in ktlint

* Don't declare functions as 'operator'

* Extend test coverage

* Make flake8 happy

* Make black happy this time :)

v1.4.2: Don't clear the output dir when generating markdown (#92)

* Don't clear the output dir when generating markdown

* Don't use distutils.dir_utils

* Fix a typo

v1.4.0: Enable the generation of Markdown docs for Glean metrics and pings (#89)

* Add a second data review to the core.yaml test file

* Add the Markdown outputter and template

This allows to produce human-readable docs
from Glean registry files.

* Add the Kotlin outputter to the translate unit

* Add test coverage for the markdown outputter

* Make flake8 and black happy

* Bonus: remove the double definition of 'description'

* Don't break the table for multiline extra keys description

* Fetch ping information for custom pings from pings.yaml

* Add a disclaimer to the Markdown template

* Bonus: mention that jinja templates are not auto generated

* Remove dead code

v1.1.0: Merge pull request #81 from mdboom/all_pings

1569765: Add check for special case of "all_pings"

v0.34.0: Enable the use of multiple categories for Gecko metrics (#79)

* Enable the use of multiple categories for Gecko metrics

This introduces a new template used for generating a
single mapping object. The object then calls in the
other generated metrics, if needed.

* Fix flake8 issues

Revert string_list -> string_set changes.

Merge pull request #78 from mozilla/revert-77-string_set

Revert "Rename 'string_list' to 'string_set'"

v0.32.0: Rename 'string_list' to 'string_set' (#77)

* Rename 'string_list' to 'string_set'

* Add test coverage for the 'string_set'

* Bonus: fix ktlint failures