Bump minimum IntelliJ version & update fork description

According to IntelliJ Plugin Verifier.

build.gradle

@@ -87,7 +87,6 @@ patchPluginXml {
     sinceBuild project.property('sinceBuild')
     untilBuild project.property('untilBuild')
     pluginDescription props.getProperty('plugin.Mypy-PyCharm.description')
-    changeNotes getChangelogHtml()
 }
 
 publishPlugin {

gradle.properties

@@ -13,10 +13,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-version=0.12.0-alpha1
+version=0.12.0-alpha2
 ideVersion=PC-2021.2.3
 pythonPlugin=PythonCore:212.5457.59
-sinceBuild=181.5684
+sinceBuild=192.7142.36
 untilBuild=
 downloadIdeaSources=true
 publishUsername=leinardi

src/main/resources/com/leinardi/pycharm/mypy/MypyBundle.properties

@@ -42,8 +42,10 @@ plugin.status.in-progress.no-file=No file is open for editing
 plugin.status.in-progress.no-module=The current file being edited does not belong to a module
 plugin.status.in-progress.project=Scanning current project...
 plugin.status.aborted=Check was aborted
-plugin.Mypy-PyCharm.description=<p>This plugin provides both real-time \
-  and on-demand scanning of Python files with Mypy from within the PyCharm IDE.</p>
+plugin.Mypy-PyCharm.description=\
+    <p>Experimental fork of the original Mypy plugin by Roberto Leinardi with various improvements.</p>\
+    <p>This plugin provides both real-time and on-demand scanning of Python files with the Mypy type checker from \
+        within the PyCharm and IntelliJ IDEs.</p>
 plugin.notification.alerts=Mypy Alerts
 plugin.notification.logging=Mypy Logging
 plugin.notification.unable-to-run-mypy.subtitle=Unable to run Mypy