Use Github Markdown on README (#3925)

* test out new Github markdown README stuff

* Change warning -> caution

Author: JasonGrace2282

README.md

@@ -21,7 +21,8 @@
 
 Manim is an animation engine for explanatory math videos. It's used to create precise animations programmatically, as demonstrated in the videos of [3Blue1Brown](https://www.3blue1brown.com/).
 
-> NOTE: This repository is maintained by the Manim Community and is not associated with Grant Sanderson or 3Blue1Brown in any way (although we are definitely indebted to him for providing his work to the world). If you would like to study how Grant makes his videos, head over to his repository ([3b1b/manim](https://github.com/3b1b/manim)). This fork is updated more frequently than his, and it's recommended to use this fork if you'd like to use Manim for your own projects.
+> [!NOTE]
+> This repository is maintained by the Manim Community and is not associated with Grant Sanderson or 3Blue1Brown in any way (although we are definitely indebted to him for providing his work to the world). If you would like to study how Grant makes his videos, head over to his repository ([3b1b/manim](https://github.com/3b1b/manim)). This fork is updated more frequently than his, and it's recommended to use this fork if you'd like to use Manim for your own projects.
 
 ## Table of Contents:
 
@@ -35,7 +36,8 @@ Manim is an animation engine for explanatory math videos. It's used to create pr
 
 ## Installation
 
-> **WARNING:** These instructions are for the community version _only_. Trying to use these instructions to install [3b1b/manim](https://github.com/3b1b/manim) or instructions there to install this version will cause problems. Read [this](https://docs.manim.community/en/stable/faq/installation.html#why-are-there-different-versions-of-manim) and decide which version you wish to install, then only follow the instructions for your desired version.
+> [!CAUTION]
+> These instructions are for the community version _only_. Trying to use these instructions to install [3b1b/manim](https://github.com/3b1b/manim) or instructions there to install this version will cause problems. Read [this](https://docs.manim.community/en/stable/faq/installation.html#why-are-there-different-versions-of-manim) and decide which version you wish to install, then only follow the instructions for your desired version.
 
 Manim requires a few dependencies that must be installed prior to using it. If you
 want to try it out first before installing it locally, you can do so