fix table delete example code in quickstart docs (unitycatalog#697)

**PR Checklist**

- [x] A description of the changes is added to the description of this
PR.
- [x] If there is a related issue, make sure it is linked to this PR.
- [ ] If you've fixed a bug or added code that should be tested, add
tests!
- [x] If you've added or modified a feature, documentation in `docs` is
updated

**Description of changes**
Changed `unity.default.my_table` to `unity.default.mytable` in
`docs/quickstart.md`.

This PR resolves issue
unitycatalog#693

Signed-off-by: Diem Phung <[email protected]>
Co-authored-by: Tathagata Das <[email protected]>

Author: gnuhpdiem

docs/quickstart.md

@@ -268,7 +268,7 @@ bin/uc table read --full_name unity.default.mytable
 Delete the table to clean up:
 
 ```bash
-bin/uc table delete --full_name unity.default.my_table
+bin/uc table delete --full_name unity.default.mytable
 ```
 
 > Note, while you have deleted the table from Unity Catalog, the underlying file system may still have the files (i.e.,