Update README.md

Co-authored-by: Thomas Labarussias <issif+github@gadz.org>
Signed-off-by: KeisukeYamashita <19yamashita15@gmail.com>

README.md

@@ -349,7 +349,7 @@ The *env vars* "match" field names in *yaml file with this structure (**take car
 * **GCP_PUBSUB_MINIMUMPRIORITY**: minimum priority of event for using this output, order is `emergency|alert|critical|error|warning|notice|informational|debug or "" (default)`
 * **GOOGLECHAT_WEBHOOKURL** : Google Chat URL (ex: https://chat.googleapis.com/v1/spaces/XXXXXX/YYYYYY), if not `empty`, Google Chat output is *enabled*
 * **GOOGLECHAT_OUTPUTFORMAT** : `all` (default), `text` (only text is displayed in Google Chat)
-* **GOOGLECHAT_MINIMUNPRIORITY** : minimum priority of event for using this output, order is `emergency|alert|critical|error|warning|notice|informational|debug or "" (default)`
+* **GOOGLECHAT_MINIMUMPRIORITY** : minimum priority of event for using this output, order is `emergency|alert|critical|error|warning|notice|informational|debug or "" (default)`
 * **GOOGLECHAT_MESSAGEFORMAT** : a Go template to format Google Chat Text above Attachment, displayed in addition to the output from `GOOGLECHAT_OUTPUTFORMAT`, see [Slack Message Formatting](#slack-message-formatting) in the README for details. If empty, no Text is displayed before sections.
 
 #### Slack/Rocketchat/Mattermost/Googlechat Message Formatting