[ci skip] update changelog

changelogs/4.0-snapshot.md

@@ -17,6 +17,9 @@ This major version features substantial changes throughout the core, including s
       - [New packet handler system](#new-packet-handler-system)
   * [API](#api)
     + [General](#general-1)
+    + [Changes to `plugin.yml`](#changes-to-pluginyml)
+      - [Permission nesting](#permission-nesting)
+      - [`src-namespace-prefix`](#src-namespace-prefix)
     + [Block](#block)
     + [Command](#command)
     + [Entity](#entity)
@@ -44,7 +47,7 @@ This major version features substantial changes throughout the core, including s
       - [Thread-local storage for AsyncTasks](#thread-local-storage-for-asynctasks)
       - [Other changes](#other-changes-1)
     + [Server](#server)
-  + [Level / World](#level---world)
+    + [Level / World](#level--world)
       - [General](#general-4)
       - [Particles](#particles)
       - [Sounds](#sounds)
@@ -145,6 +148,57 @@ This version features substantial changes to the network system, improving coher
 - `void` and `?nullable` parameter and return types have been applied in many places.
 - Everything in the `pocketmine\metadata` namespace and related implementations have been removed.
 
+### Changes to `plugin.yml`
+#### Permission nesting
+Permission nesting is no longer supported in `plugin.yml`. Grouping permissions (with defaults) in `plugin.yml` had very confusing and inconsistent behaviour.
+Instead of nesting permission declarations, they should each be declared separately.
+
+_Before_:
+```
+permissions:
+   pmmp:
+     default: op
+	 children:
+	     pmmp.something:
+		     default: op
+         pmmp.somethingElse
+		     default: op
+```
+
+_After_:
+```
+permissions:
+    pmmp.something:
+        default: op
+    pmmp.somethingElse
+        default: op
+```
+
+#### `src-namespace-prefix`
+A new directive `src-namespace-prefix` has been introduced. This allows you to get rid of those useless subdirectories in a plugin's structure.
+For example, a plugin whose main was `pmmp\TesterPlugin\Main` used to have to be structured like this:
+```
+|-- plugin.yml
+|-- src/
+    |-- pmmp/
+        |-- TesterPlugin/
+            |-- Main.php
+	        |-- SomeOtherClass.php
+	        |-- SomeNamespace/
+	            |-- SomeNamespacedClass.php
+```
+However, if we add `src-namespace-prefix: pmmp\TesterPlugin` to the `plugin.yml`, now we can get rid of the useless directories and structure it like this instead:
+```
+|-- plugin.yml
+|-- src/
+    |-- Main.php
+    |-- SomeOtherClass.php
+	|-- SomeNamespace/
+	    |-- SomeNamespacedClass.php
+```
+
+**Note**: The old structure will also still work just fine. This is not a required change.
+
 ### Block
 - A new `VanillaBlocks` class has been added, which contains static methods for creating any currently-known block type. This should be preferred instead of use of `BlockFactory::get()` where constants were used.
 - Blocks now contain their positions instead of extending `Position`. `Block->getPos()` has been added.