Updating discord workflow (#475)

* Updating docker action

* adding version to message

* adding way to get PR title and body

* Adding input pass to workflows

Workflow dispatches may not get push header info. Switching logic to pass needed title and body info through just in case.

* adding token

The description on this action is awful, it didn't mention needing a token. I found this solution from the repo's issues

* parsing pr body

* Updating parsing

* Updating docker workflow

.github/workflows/nightly-docker.yml

@@ -92,4 +92,3 @@ jobs:
           webhook: ${{ secrets.DISCORD_DOCKER_UPDATE_URL }}
           message: "A new nightly build v${{steps.get-version.outputs.assembly-version}} has been released for docker.\nhttps://hub.docker.com/r/kizaing/kavita/tags?page=1&ordering=last_updated"
           embed: '{ "title": "${{ github.event.inputs.title }}", "description": "${{ github.event.inputs.body }}", "url": "{{ commit.url }}", "author": { "name": "{{ commit.author.name }} ({{ commit.author.username }})", "icon_url": "https://avatars.io/gravatar/{{ commit.author.email }}"} }'
-          last-commit-only: true