chore: remove statement about being under development (backport #95) (#99)

This is an automatic backport of pull request #95 done by [Mergify](https://mergify.com).


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Author: mergify[bot]

README.md

@@ -7,8 +7,6 @@
 
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-> This library is currently under development. Do not use!
-
 <!--END STABILITY BANNER-->
 
 This module exports a single class called `KubectlV22Layer` which is a `lambda.LayerVersion` that