Various updates.

.gitmodules

@@ -1,6 +1,6 @@
-[submodule "buildscripts"]
-	path = buildscripts
-	url = https://github.com/MonoGame/MonoGame.Library.BuildScripts.git
 [submodule "basis_universal"]
 	path = basis_universal
 	url = https://github.com/BinomialLLC/basis_universal.git
+[submodule "buildscripts"]
+	path = buildscripts
+	url = https://github.com/MonoGame/MonoGame.Tool.BuildScripts.git

README.md

@@ -1,2 +1,36 @@
 # MonoGame.Tool.BasisUniversal
 MonoGame tooling build for basis_universal
+
+This tool can be used to compress an image into various texture compression
+formats. Examples are BC1-7, PVRTC, ETC1, ETC2, ASTC and ATC.
+
+To use we must first create a "basis" file, this is an intermediate file containing
+the image data. From this file ALL over texture formats can be created. It is probably
+worth caching this "basis" file between builds.
+
+```dotnetcli
+basisu -file foo.png -ktx2
+```
+
+Adding a `-uastc` might give better results for some compression types.
+
+Once you have the "basis" file you can then transform that into specific formats
+by using the `-unpack` command. PRoviding the `-format_only` flag will produce
+ONLY that format. Omitting this flag will result in ALL supported formats being
+produced.
+
+```dotnetcli
+basisu -unpack foo.ktx2 -no_ktx -linear -format_only 2
+```
+
+The output file(s) are listed in the output. There may be many output files. They will be stored in a .png files, but the internal image data will be compressed. We can use libraries like StbImageSharp to read the .png data.
+
+```csharp
+using (var fs = File.OpenRead(filename))
+{
+    ImageResult result = ImageResult.FromStream(fs, StbImageSharp.ColorComponents.Default);
+    return result.Data;
+}
+```
+
+If mipmap's are enabled, you will get one .png per mipmap level.

build/BuildMacOSTask.cs

@@ -1,5 +1,3 @@
-using System.Runtime.InteropServices;
-
 namespace BuildScripts;
 
 [TaskName("Build macOS")]