github/actions: add auto-assign list

.github/auto_assign.yml

+# Set to true to add reviewers to pull requests
+addReviewers: true
+
+# Set to true to add assignees to pull requests
+addAssignees: false
+
+# A list of reviewers to be added to pull requests (GitHub user name)
+reviewers:
+  - Stebalien
+  - djdv
+  - aschmahmann
+  - dirkmc
+  - lanzafame
+  - hsanjuan
+
+# A number of reviewers added to the pull request
+# Set 0 to add all the reviewers (default: 0)
+numberOfReviewers: 1
+
+# A list of assignees, overrides reviewers if set
+# assignees:
+#   - assigneeA
+
+# A list of keywords to be skipped the process that add reviewers if pull requests include it
+skipKeywords:
+  - WIP
+  - RFC