doc: fix structure and formatting in inspector.md

1. Reorder some sections alphabetically.
2. Fix some heading levels.
3. Express a type of a property more formally.

PR-URL: #21709
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Claudio Rodriguez <cjrodr@yahoo.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>

doc/api/inspector.md

@@ -12,6 +12,21 @@ It can be accessed using:
 const inspector = require('inspector');
 ```
 
+## inspector.close()
+
+Deactivate the inspector. Blocks until there are no active connections.
+
+## inspector.console
+
+* {Object} An object to send messages to the remote inspector console.
+
+```js
+require('inspector').console.log('a message');
+```
+
+The inspector console does not have API parity with Node.js
+console.
+
 ## inspector.open([port[, host[, wait]]])
 
 * `port` {number} Port to listen on for inspector connections. Optional.
@@ -28,22 +43,7 @@ started.
 If wait is `true`, will block until a client has connected to the inspect port
 and flow control has been passed to the debugger client.
 
-### inspector.console
-
-An object to send messages to the remote inspector console.
-
-```js
-require('inspector').console.log('a message');
-```
-
-The inspector console does not have API parity with Node.js
-console.
-
-### inspector.close()
-
-Deactivate the inspector. Blocks until there are no active connections.
-
-### inspector.url()
+## inspector.url()
 
 * Returns: {string|undefined}
 
@@ -112,6 +112,16 @@ Connects a session to the inspector back-end. An exception will be thrown
 if there is already a connected session established either through the API or by
 a front-end connected to the Inspector WebSocket port.
 
+### session.disconnect()
+<!-- YAML
+added: v8.0.0
+-->
+
+Immediately close the session. All pending message callbacks will be called
+with an error. [`session.connect()`] will need to be called to be able to send
+messages again. Reconnected session will lose all inspector state, such as
+enabled agents or configured breakpoints.
+
 ### session.post(method[, params][, callback])
 <!-- YAML
 added: v8.0.0
@@ -139,16 +149,6 @@ by V8. Chrome DevTools Protocol domain provides an interface for interacting
 with one of the runtime agents used to inspect the application state and listen
 to the run-time events.
 
-### session.disconnect()
-<!-- YAML
-added: v8.0.0
--->
-
-Immediately close the session. All pending message callbacks will be called
-with an error. [`session.connect()`] will need to be called to be able to send
-messages again. Reconnected session will lose all inspector state, such as
-enabled agents or configured breakpoints.
-
 ## Example usage
 
 ### CPU Profiler