Simplify dependency management

Use dependencyManagement for versioning shared dependencies
Use pluginManagement for versioning and configuring plugins

README.MD

@@ -15,48 +15,7 @@ OpenInv is a [Bukkit plugin](https://dev.bukkit.org/bukkit-plugins/openinv/) whi
 - **AnyContainer**: Open containers, even if blocked by ocelots or blocks.
 
 ## Commands
-<table width=100%>
-  <tr>
-    <th width=175px>Command</th>
-    <th>Aliases</th>
-    <th>Description</th>
-  </tr>
-  <tr>
-    <td>/openinv [player]</td>
-    <td>oi, inv, open</td>
-    <td>Open a player's inventory. If unspecified, will select last player opened or own if none opened previously.</td>
-  </tr>
-  <tr>
-    <td>/openender [player]</td>
-    <td>oe</td>
-    <td>Open a player's ender chest. If unspecified, will select last player opened or own if none opened previously.</td>
-  </tr>
-  <tr>
-    <td>/searchinv &ltitem&gt [minAmount]</td>
-    <td>si</td>
-    <td>Lists all online players that have a certain item in their inventory.</td>
-  </tr>
-  <tr>
-    <td>/searchender &ltitem&gt [minAmount]</td>
-    <td>se</td>
-    <td>Lists all online players that have a certain item in their ender chest.</td>
-  </tr>
-  <tr>
-    <td>/searchenchant &lt[enchantment] [MinLevel]&gt</td>
-    <td>searchenchants</td>
-    <td>Lists all online players with a specific enchantment.</td>
-  </tr>
-  <tr>
-    <td>/anycontainer [check]</td>
-    <td>ac, anychest</td>
-    <td>Check or toggle the AnyContainer function, allowing opening blocked containers.</td>
-  </tr>
-  <tr>
-    <td>/silentcontainer [check]</td>
-    <td>sc, silentchest</td>
-    <td>Check or toggle the SilentContainer function, allowing opening containers silently.</td>
-  </tr>
-</table>
+See [the wiki](https://github.com/Jikoo/OpenInv/wiki/Commands).
 
 ## Permissions
 <table>
@@ -143,8 +102,39 @@ OpenInv is a [Bukkit plugin](https://dev.bukkit.org/bukkit-plugins/openinv/) whi
 </table>
 
 ## For Developers
-To compile, the relevant Craftbukkit/Spigot jars must be installed in your local repository using the install plugin.
-Ex: `mvn install:install-file -Dpackaging=jar -Dfile=spigot-1.8-R0.1-SNAPSHOT.jar -DgroupId=org.spigotmc -DartifactId=spigot -Dversion=1.8-R0.1-SNAPSHOT`
+
+### As a Dependency
+The OpenInv API is available via [JitPack](https://jitpack.io/).
+```xml
+  <repositories>
+    <repository>
+      <id>jitpack.io</id>
+      <url>https://jitpack.io</url>
+    </repository>
+  </repositories>
+```
+```xml
+  <dependencies>
+    <dependency>
+      <groupId>com.github.jikoo.OpenInv</groupId>
+      <artifactId>openinvapi</artifactId>
+      <version>${openinv.version}</version>
+    </dependency>
+  </dependencies>
+```
+
+### Compilation
+To compile, the relevant Spigot jars must be installed in your local repository using the `install` plugin:
+```shell
+mvn install:install-file -Dpackaging=jar -Dfile=spigot-1.8-R0.1-SNAPSHOT.jar \
+    -DgroupId=org.spigotmc -DartifactId=spigot -Dversion=1.8-R0.1-SNAPSHOT
+```
+Note that BuildTools automatically installs produced files. If you use BuildTools to compile Spigot locally, you don't need to install it manually.  
+If you want to use Paper as a dependency, you can install it by executing PaperClip with the property `paperclip.install` set to true:
+```shell
+wget -O paperclip.jar https://papermc.io/api/v1/paper/1.16.5/latest/download
+java -jar -Dpaperclip.install=true paperclip.jar
+```
 
 To compile for a single version, specify the NMS revision you are targeting: `mvn -pl <NMS module> -am clean install`
 
@@ -153,20 +143,3 @@ To compile for a set of versions, you'll need to use a profile. The only provide
 For more information, check out the [official Maven guide](http://maven.apache.org/guides/introduction/introduction-to-profiles.html).
 
 The final file is `target/OpenInv.jar`
-
-## License
-```
-Copyright (C) 2011-2020 lishid. All rights reserved.
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, version 3.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program. If not, see <http://www.gnu.org/licenses/>.
-```