Minor flutter daemon doc fixes (#18447)

* Fix anchors for GitHub

For some reason GitHub lowercases the anchor names so although these links all work in the local VS Code preview, the ones with capitals didn't work in the GitHub UI!

* Fix some typos

packages/flutter_tools/doc/daemon.md

@@ -65,12 +65,12 @@ The `daemon.connected` event is sent when the daemon starts. The `params` field
 
 #### daemon.logMessage
 
-The `daemon.logMessage` event is sent whenever a log message is created - either a status level message or an error. The JSON message will contains an `event` field with the value `daemon.logMessage`, and an `params` field containing a map with `level`, `message`, and (optionally) `stackTrace` fields.
+The `daemon.logMessage` event is sent whenever a log message is created - either a status level message or an error. The JSON message will contain an `event` field with the value `daemon.logMessage`, and an `params` field containing a map with `level`, `message`, and (optionally) `stackTrace` fields.
 
 
 #### daemon.showMessage
 
-The `daemon.showMessage` event is sent by the daemon when some if would be useful to show a message to the user. This could be an error notification or a notification that some development tools are not configured or not installed. The JSON message will contains an `event` field with the value `daemon.showMessage`, and an `params` field containing a map with `level`, `title`, and `message` fields. The valid options for `level` are `info`, `warning`, and `error`.
+The `daemon.showMessage` event is sent by the daemon when some if would be useful to show a message to the user. This could be an error notification or a notification that some development tools are not configured or not installed. The JSON message will contain an `event` field with the value `daemon.showMessage`, and an `params` field containing a map with `level`, `title`, and `message` fields. The valid options for `level` are `info`, `warning`, and `error`.
 
 It is up to the client to decide how best to display the message; for some clients, it may map well to a toast style notification. There is an implicit contract that the daemon will not send too many messages over some reasonable period of time.
 
@@ -205,7 +205,7 @@ The following subset of the daemon domain is available in `flutter run --machine
   - [`shutdown`](#daemonshutdown)
 - Events
   - [`connected`](#daemonconnected)
-  - [`logMessage`](#daemonlogMessage)
+  - [`logMessage`](#daemonlogmessage)
 
 ### app domain
 
@@ -213,11 +213,11 @@ The following subset of the app domain is available in `flutter run --machine`.
 
 - Commands
   - [`restart`](#apprestart)
-  - [`callServiceExtension`](#appcallServiceExtension)
+  - [`callServiceExtension`](#appcallserviceextension)
   - [`stop`](#appstop)
 - Events
   - [`start`](#appstart)
-  - [`debugPort`](#appdebugPort)
+  - [`debugPort`](#appdebugport)
   - [`started`](#appstarted)
   - [`log`](#applog)
   - [`progress`](#appprogress)