Social SDK: Add Supported Mobile Minimum Versions (#8028)

Adding to platform compatability matrix.

Author: markmandel

docs/discord-social-sdk/core-concepts/platform-compatibility.mdx

@@ -23,8 +23,8 @@ The Discord Social SDK is available for the following platforms:
 | macOS (ARM64) | 11 | Generally Available | ✅ | ❌ | ✅ |
 | Linux | glibc 2.31* | Experimental | ✅ | ✅ | ✅ |
 | **Mobile** | | | | | |
-| Android |   | Experimental | ✅ | ❌ | ✅ |
-| iOS |   | Experimental | ✅ | ❌ | ✅ |
+| Android | 7.0 | Experimental | ✅ | ❌ | ✅ |
+| iOS | 15.1 | Experimental | ✅ | ❌ | ✅ |
 | **Console** | | | | | |
 | Xbox One | | Experimental | ✅ | ✅ | ❌ |
 | Xbox Series X\|S | | Experimental | ✅ | ✅ | ✅ |