Minor tweaks to hooks section in readme

README.md

@@ -922,8 +922,8 @@ firing a JSON webhook. These variables include:
 - `MRSK_RECORDED_AT` - UTC timestamp in ISO 8601 format, e.g. `2023-04-14T17:07:31Z`
 - `MRSK_PERFORMER` - the local user performing the command (from `whoami`)
 - `MRSK_SERVICE_VERSION` - an abbreviated service and version for use in messages, e.g. app@150b24f
-- `MRSK_VERSION` - an full version being deployed
-- `MRSK_HOSTS` - a comma separated list of the hosts targeted by the command
+- `MRSK_VERSION` - the full version being deployed
+- `MRSK_HOSTS` - a comma-separated list of the hosts targeted by the command
 - `MRSK_COMMAND` - The command we are running
 - `MRSK_SUBCOMMAND` - optional: The subcommand we are running
 - `MRSK_DESTINATION` - optional: destination, e.g. "staging"
@@ -940,9 +940,8 @@ Used for pre-build checks - e.g. there are no uncommitted changes or that CI has
 3. pre-deploy
 For final checks before deploying, e.g. checking CI completed
 
-3. post-deploy - run after a deploy, redeploy or rollback
-
-This hook is also passed a `MRSK_RUNTIME` env variable.
+3. post-deploy - run after a deploy, redeploy or rollback.
+This hook is also passed a `MRSK_RUNTIME` env variable set to the total seconds the deploy took.
 
 This could be used to broadcast a deployment message, or register the new version with an APM.
 
@@ -953,7 +952,7 @@ The command could look something like:
 curl -q -d content="[My App] ${MRSK_PERFORMER} Rolled back to version ${MRSK_VERSION}" https://3.basecamp.com/XXXXX/integrations/XXXXX/buckets/XXXXX/chats/XXXXX/lines
 ```
 
-That'll post a line like follows to a preconfigured chatbot in Basecamp:
+That'll post a line like the following to a preconfigured chatbot in Basecamp:
 
 ```
 [My App] [dhh] Rolled back to version d264c4e92470ad1bd18590f04466787262f605de