pyproject: Include MIGRATION in sdist (#517)

Author: tony

CHANGES

@@ -14,6 +14,10 @@ $ pip install --user --upgrade --pre libtmux
 
 <!-- Maintainers and contributors: Insert change notes for the next release above -->
 
+### Packaging
+
+- Include `MIGRATION` in source distribution tarball (#517, for #508)
+
 ## libtmux 0.27.0 (2024-02-07)
 
 ### Improvement

pyproject.toml

@@ -33,6 +33,7 @@ packages = [
 ]
 include = [
   { path = "CHANGES", format = "sdist" },
+  { path = "MIGRATION", format = "sdist" },
   { path = ".tmuxp.yaml", format = "sdist" },
   { path = "tests", format = "sdist" },
   { path = "docs", format = "sdist" },