Markdown list issue in tutorials' `README.md`

[coffee-squirrel]

Lists in tuts/*/README.md are using • instead of a Markdown-friendly character (e.g. *, -, +), impacting readability.

Example: https://github.com/aws-samples/sample-developer-tutorials/blob/982b965efccc3fa5f67fecece9824f28926c77bc/tuts/003-s3-gettingstarted/README.md#resources-created

[mwunderl]

fixed in #22