Add release instructions

Author: wetneb

README.md

@@ -1,14 +1,14 @@
 Commons extension (name not final)
 ==================================
 
-This is a skeleton of OpenRefine extension for Wikimedia Commons, in the form of an independent Maven project.
+This is an OpenRefine extension for Wikimedia Commons.
 It works with OpenRefine 3.6+.
 
 
 Building it
 -----------
 
-Run
+Run     
 ```
 mvn package
 ```
@@ -20,3 +20,15 @@ Developing it
 
 To avoid having to unzip the extension in the corresponding directory every time you want to test it, you can also use another set up: simply create a symbolic link from your extensions folder in OpenRefine to the local copy of this repository.
 You will still need to restart OpenRefine every time you make changes.
+
+Releasing it
+------------
+
+- Open `pom.xml` and set the version to the desired version number, such as `<version>0.1.0</version>`
+- Commit and push those changes
+- Add a corresponding git tag, with `git tag -a v0.1.0 -m "Version 0.1.0"`
+- Push the tag to GitHub: `git push --tags`
+- Create the zip file for the release: `mvn package`
+- Create a new release on GitHub at https://github.com/OpenRefine/CommonsExtension/releases/new, providing a release title (such as "Commons extension 0.1.0") and a description of the features in this release. Upload the zip file you generated at the previous step as an attachment (it can be found in the `target` subfolder of your local copy of the repository).
+- Open `pom.xml` and set the version to the expected next version number, followed by `-SNAPSHOT`. For instance, if you just released 0.1.0, you could set `<version>0.1.1-SNAPSHOT</version>`
+- Commit and push those changes.

pom.xml

@@ -4,7 +4,7 @@
 
   <groupId>org.openrefine.extensions</groupId>
   <artifactId>refine-commons-extension</artifactId>
-  <version>0.1.0</version>
+  <version>0.1.0-SNAPSHOT</version>
   <packaging>jar</packaging>
 
   <name>OpenRefine - Commons extension</name>