Update create-a-multiple-container-fragment.md: INDENT FIX

[lkdhy]

📚 Context

This is a slight change, fixing some indent bugs.

I'm a bit confused when I read the code displayed in https://docs.streamlit.io/develop/tutorials/execution-flow/create-a-multiple-container-fragment#frame-out-your-apps-containers.

Specifically, the line of st.markdown("🐾 🐾 🐾 🐾"), in both functions black_cats() and orange_cats() (see screenshots (Current) below), seem to miss an indent. This complies with neither my intuition nor [https://docs.streamlit.io/develop/tutorials/execution-flow/create-a-multiple-container-fragment#summary](the full demo code depicted above on this page).

Obviously, the cats and their footprints should be in the same containers and rendered simultaneously.

🧠 Description of Changes

Nothing more than:

• add indents to get this bug fixed

Revised:

Current:

[sfc-gh-dmatthews]

Thanks!