Add minor changeset for SDK README updates (#1234)

## Summary
- Adds a minor changeset for both `e2b` (JS SDK) and `@e2b/python-sdk`
(Python SDK) to publish updated READMEs

## Test plan
- [ ] Verify changeset format is correct
- [ ] Confirm version bump triggers on merge

Author: beran-t

.changeset/update-sdk-readmes.md

@@ -0,0 +1,6 @@
+---
+'e2b': minor
+'@e2b/python-sdk': minor
+---
+
+Update SDK READMEs