add a README file

.hgignore

@@ -1 +1,5 @@
 ^.venv/
+^settings\.cfg$
+^sftp-config\.json$
+^incident-handler\.sublime-project$
+^incident-handler\.sublime-workspace$

README.md

@@ -0,0 +1,24 @@
+Example `settings.cfg` file:
+
+```python
+FIH_ROOT = "/home/status/incident_handler"
+STATUS_ROOT = "/home/status/status.example.com"
+STATUS_EVENT_SCHEME = STATUS_ROOT + "/content/event/%(incident_number)s-%(slug)s.md"
+STATUS_EVENT_GLOB = STATUS_ROOT + "/content/event/%(incident_number)s*.md"
+STATUS_EVENT_INDEX = STATUS_ROOT + "/content/pages/index.md"
+MERCURIAL_BIN = "/usr/bin/hg"
+GROW_BIN = "/usr/local/bin/grow"
+MERCURIAL_PUSH_TO = [ "c3", "c4" ]
+GROW_DEPLOY_TO = [ "c3", "c4" ]
+
+MATTERMOST_COMMAND_TOKENS = [ "XXXXXXXXXXXXXXXXXXXXXXXXXX" ]
+MATTERMOST_USER_EMAIL = "mattermostuser@example.com"
+MATTERMOST_USER_PASSWORD = "XXXXXXXXXXXXXXXX"
+MATTERMOST_URL = "mattermost.example.com"
+MATTERMOST_PORT = 443
+
+MATTERMOST_INCIDENT_CHANNEL_PREFIX = "incident"
+PUBLIC_INCIDENT_PREFIX = "FI#"
+STATUS_PAGE_URL = "https://status.faelix.net/"
+INCIDENT_URL_SCHEME = STATUS_PAGE_URL + "event/%s/"
+```