[monorepo] Add changeset to checks (#2061)
[monorepo] Add changeset to checks (#2061)

* Add changeset to checks

* Make sure we have the main branch available for changeset to search

* Fix changeset ability to search main history

* Try again

* Test should cause changeset error

* Revert test error
lit/lit,Polymer/lit-html,lit/lit,Polymer/lit-html,Polymer/lit-html,lit/lit,Polymer/lit-html,lit/lit