Add versioning.

Directory.Build.props

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <PackageReference Include="Nerdbank.GitVersioning">
+      <Version>3.3.37</Version>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+</Project>

MapTo/Mapto.csproj

@@ -1,6 +1,10 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <LangVersion>9</LangVersion>
+        
         <AssemblyName>MapTo</AssemblyName>
         <Description>An object to object mapping generator using using Roslyn code generator.</Description>
         <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
@@ -14,9 +18,6 @@
         <RepositoryUrl>https://github.com/mrtaikandi/mapto</RepositoryUrl>
         <SymbolPackageFormat>snupkg</SymbolPackageFormat>
         <RootNamespace>MapTo</RootNamespace>
-        <TargetFramework>netstandard2.0</TargetFramework>
-        <Nullable>enable</Nullable>
-        <LangVersion>9</LangVersion>
     </PropertyGroup>
 
     <ItemGroup>

version.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
+  "version": "1.0.0-alpha",
+  "publicReleaseRefSpec": [
+    "^refs/heads/master$",
+    "^refs/heads/v\\d+(?:\\.\\d+)?$"
+  ],
+  "cloudBuild": {
+    "buildNumber": {
+      "enabled": true
+    }
+  }
+}