Update README.md

Source file https://github.com/dry-rb/template-gem/blob/HEAD/README.md.erb

Author: File Sync

README.md

@@ -14,7 +14,7 @@
 
 This library officially supports the following Ruby versions:
 
-* MRI `2.7`
+* MRI `>= 2.7.0`
 * jruby `>= 9.4` (not tested on CI)
 
 ## License