Merge pull request #1 from nijave/nv-upgrade-instructions

Add update instructions

README.md

@@ -4,4 +4,17 @@
 Install using Powershell to run `install.ps1`
 ```
 @"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command "iex ((New-Object System.Net.WebClient).DownloadString('https://github.com/nijave/borg-windows-package/releases/download/latest/install.ps1'))"
-```
+```
+
+## Update
+Update cygwin (from Windows)
+```
+C:\tools\cygwin\cygwinsetup.exe --no-desktop --no-shortcuts --no-startmenu --quiet-mode
+```
+Upgrade borgbackup
+```
+rm borgbackup*.whl
+LATEST_WHL=$(curl -s https://github.com/gitapi/repos/nijave/borg-windows-package/releases/latest | grep -E "https://.*?\.whl" | cut -d '"' -f 4)
+curl -LO "$LATEST_WHL"
+pip install -U borgbackup*.whl borgmatic
+```