github: Sync PRs to JIRA as well

Currently the GitHub sync half-syncs these (as it will create a JIRA issue as soon as the first
comment is made on the PR).

.github/main.workflow

@@ -3,11 +3,16 @@ workflow "Sync issues to JIRA" {
   resolves = ["Sync to JIRA"]
 }
 
-workflow "Sync issue comments to JIRA" {
+workflow "Sync issue and PR comments to JIRA" {
   on = "issue_comment"
   resolves = ["Sync to JIRA"]
 }
 
+workflow "Sync PRs to JIRA" {
+  on = "pull_request"
+  resolves = ["Sync to JIRA"]
+}
+
 action "Sync to JIRA" {
   uses = "espressif/github-actions/sync_issues_to_jira@master"
   secrets = ["GITHUB_TOKEN", "JIRA_URL", "JIRA_USER", "JIRA_PASS"]