Update machine restart policy docs

machines/guides-examples/machine-restart-policy.html.markerb

@@ -13,7 +13,7 @@ The restart policies are:
 
 - **`always`**: Always restart a Machine automatically and never let it enter a `stopped` state, even when the main process exits cleanly. `always` is the default when you create a Machine with `fly m run` and for Fly Postgres app Machines. Recommended for "always-on" apps with no services configured, since the Machine restarts regardless of the exit code.
 
-- **`on-fail`** (or **`on-failure`** for the Machines API and when viewed in the Machine config): Try up to 10 times to automatically restart the Machine if it exits with a non-zero exit code, before letting it stop. Recommended for most Machines with services configured, since Fly Proxy can wake them on request. `on-fail` lets Machines be restarted if they crash, and allows your app Machines to effectively scale down by exiting cleanly. `on-fail` is the default when there's no explicit restart policy in a Machine's config, such as Machines created by `fly launch` and `fly deploy`. Machines with a schedule also default to the `on-fail` restart policy.
+- **`on-fail`** (or **`on-failure`** for the Machines API and when viewed in the Machine config): Try up to `max_retries` (default 10) times within a 5-minute window to automatically restart the Machine if it exits with a non-zero exit code, before letting it stop. Recommended for most Machines with services configured, since Fly Proxy can wake them on request. `on-fail` lets Machines be restarted if they crash, and allows your app Machines to effectively scale down by exiting cleanly. `on-fail` is the default when there's no explicit restart policy in a Machine's config, such as Machines created by `fly launch` and `fly deploy`. Machines with a schedule also default to the `on-fail` restart policy.
 
 ## Check a Machine's restart policy
 
@@ -95,13 +95,13 @@ For example:
 
 Refer to the Machines API docs for more information about [updating a Machine](/docs/machines/api-machines-resource/#update-a-machine).
 
-## Set a restart policy in your Fly.toml
-You can also set a default app-level restart policy in your Fly.toml file:
+## Set a restart policy in your fly.toml
+You can also set a default app-level restart policy in your fly.toml file:
 ```toml
 [[restart]]
   policy = "<never | always | on-failure>"
   retries = 10
   processes = ["app"]
 ```
 
- A restart policy can be targeted to a specific process group. If a group is not specified, all machines in an app will have the same default restart policy. If needed, you can still apply different policies on individual machines using the Flyctl or Machines API methods above.
+ A restart policy can be targeted to a specific process group. If a group is not specified, all machines in an app will have the same default restart policy. If needed, you can still apply different policies on individual machines using the flyctl or Machines API methods above.