add readme (#14)

Author: ateoi

README.md

@@ -0,0 +1,41 @@
+# JetBrainsMono Nerd Font installer for Windows
+
+This is a [WiX v3](https://wixtoolset.org/docs/v3/) based installer for the
+[JetBrainsMono Nerd Font](https://www.nerdfonts.com/).
+
+## Build prerequisites
+
+- [Visual Studio 2022 (any edition)](https://visualstudio.microsoft.com/#vs-section)
+- [WiX v3](https://wixtoolset.org/docs/wix3/) (if packaging on Windows)
+- [WiX v3 - Visual Studio 2022 Extension](https://marketplace.visualstudio.com/items?itemName=WixToolset.WixToolsetVisualStudio2022Extension)
+
+WiX v3 is available at <https://github.com/wixtoolset/wix3/releases/>. It
+requires .NET Framework 3.5, which can be installed with the following command:
+
+```powershell
+Start-Process `
+    -FilePath pwsh `
+    -ArgumentList "-Command `"& {Enable-WindowsOptionalFeature -Online -FeatureName NetFx3}`"" `
+    -Wait `
+    -Verb RunAs
+```
+
+Update your path environment with `setx` (supposing you installed the tools in
+their default directories):
+
+```powershell
+setx PATH ($(Get-ItemProperty -Path HKCU:\Environment -Name Path).Path + "${env:ProgramFiles(x86)}\WiX Toolset v3.11\bin")
+```
+
+Check if `PATH` was set correctly:
+
+```
+Get-Command candle
+```
+
+## Build
+
+Run the `Build-Installer.ps1` PowerShell script to build the installer.
+
+If successful, the MSI file will be available in the
+`JetBrainsMonoNF\bin\Release` directory.