[README.md] update installer links for v0.7.1

Author: chrissimpkins

README.md

@@ -10,8 +10,10 @@ Slice is an open-source, cross-platform GUI app that generates fonts with custom
 
 ## Install
 
-* macOS: [Slice.0.7.0.dmg](https://github.com/source-foundry/Slice/releases/download/v0.7.0/Slice.0.7.0.dmg)
-* Windows: [Slice-0.7.0-Installer.exe](https://github.com/source-foundry/Slice/releases/download/v0.7.0/Slice-0.7.0-Installer.exe)
+* macOS: [Slice.0.7.1.dmg](https://github.com/source-foundry/Slice/releases/download/v0.7.1/Slice.0.7.1.dmg)
+* Windows: [Slice-0.7.1-Installer.exe](https://github.com/source-foundry/Slice/releases/download/v0.7.1/Slice-0.7.1-Installer.exe)
+
+Please see the [Installation docs](https://slice-gui.netlify.app/docs/install/) for additional details, including available package manager installation/upgrade approaches.
 
 ## User documentation