Update docs/EXTERNAL_CHECK_CREATION.md
add link to README
@@ -22,7 +22,7 @@ Your check only needs to do a few things:
- Read the `KH_REPORTING_URL` environment variable.
- Send a `POST` to the `KH_REPORTING_URL` with the following JSON body:
-- Ensure that your check finishes within the `unix` deadline specified in the `KH_CHECK_RUN_DEADLINE` environment variable. Without respecting `KH_CHECK_RUN_DEADLINE`, your check may run into a `400` error returned from Kuberhealthy when reporting your check's status.
+- Ensure that your check finishes within the [unixtime](https://en.wikipedia.org/wiki/Unix_time) deadline specified in the `KH_CHECK_RUN_DEADLINE` environment variable. If `KH_CHECK_RUN_DEADLINE` is not rexpected, your check may run into a `400` error when reporting state to Kuberhealthy.
```json
{
