chore: Bump version to 2.3.0 (#969)

#### Details

#967 added new functionality, so our next release ought to reflect this.
This moves from 2.2.1 to 2.3.0

##### Motivation

Follow semver guidelines

##### Context

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#### Pull request checklist
<!-- If a checklist item is not applicable to this change, write "n/a"
in the checkbox -->
- [n/a] Addresses an existing issue:

src/CLI/README.MD

@@ -16,7 +16,7 @@ You invoke the scanner by running `AxeWindowsCLI.exe`. By default, this tool get
 If you run the tool without parameters, you'll be presented with the help screen. An example follows:
 
 ```
-AxeWindowsCLI 2.2.1
+AxeWindowsCLI 2.3.0
 Copyright c 2020
 
   --processid                 Process Id

src/props/version.props

@@ -1,6 +1,6 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <SemVerNumber Condition="$(SemVerNumber) == ''">2.2.1</SemVerNumber>
+    <SemVerNumber Condition="$(SemVerNumber) == ''">2.3.0</SemVerNumber>
     <SemVerSuffix></SemVerSuffix>
   </PropertyGroup>
 </Project>