Update index.md (MystenLabs#997)

* Update index.md

Removing broken YouTube embeddings

* Update index.md

Fix iframes by pulling from list
Make bullets sections

doc/src/explore/index.md

@@ -2,18 +2,27 @@
 title: Exploring Sui
 ---
 
-Now that you've [learned](../learn/index.md) about Sui and started [building](../build/index.md) it, use the contents of this section to delve into Sui more deeply by:
+Now that you've [learned](../learn/index.md) about Sui and started [building](../build/index.md) it, use the contents of this section to delve into Sui more deeply.
 
-* Taking an end-to-end [tutorial](../explore/tutorials.md) from starting a Sui network locally to publishing a TicTacToe game on Sui and playing it.
-* Trying out [examples](../explore/examples.md) supplied by the Sui team to help you understand how objects are structured and manipulated.
-* Viewing projects built by third parties demonstrating the power of Sui.
-  * [Prototypes](prototypes.md) pre-alpha game prototypes that showcase the power of NFTs on Sui.
+## Tutorial
+Taking an end-to-end [tutorial](../explore/tutorials.md) from starting a Sui network locally to publishing a TicTacToe game on Sui and playing it.
+
+## Examples
+Try out [examples](../explore/examples.md) supplied by the Sui team to help you understand how objects are structured and manipulated.
+
+## Prototypes
+View projects built by third parties demonstrating the power of Sui.
+
+[Prototypes](prototypes.md) pre-alpha game prototypes that showcase the power of NFTs on Sui:
 <section class="sui-dev-video">
-   <iframe id="ytplayer" type="text/html" src="https://www.youtube.com/embed/sAMT5x8W3B8?autoplay=0"  frameborder="0"></iframe>
+
+<iframe id="ytplayer" type="text/html" src="https://www.youtube.com/embed/sAMT5x8W3B8?autoplay=0"  frameborder="0"></iframe>
 </section>
-  * [Panzerdogs x Sui](panzerdogs.md) is an NFT gaming project where users can own their in-game assets and use them to battle against each other in tanks. Brawl Stars x Tanks x Play-To-Earn.
-  * [SoWork x Sui](sowork.md) building features on Sui to power creative employee rewards and custom NFT mints via SoWork's mapmaker.
+
+[Panzerdogs x Sui](panzerdogs.md) is an NFT gaming project where users can own their in-game assets and use them to battle against each other in tanks. Brawl Stars x Tanks x Play-To-Earn.
+
+[SoWork x Sui](sowork.md) building features on Sui to power creative employee rewards and custom NFT mints via SoWork's mapmaker.
 <section class="sui-dev-video">
-   <iframe id="ytplayer" type="text/html" src="https://www.youtube.com/embed/lwPMhpiyfmE?autoplay=0"  frameborder="0"></iframe>
-</section>
 
+ <iframe id="ytplayer" type="text/html" src="https://www.youtube.com/embed/lwPMhpiyfmE?autoplay=0"  frameborder="0"></iframe>
+</section>