Format headings and add descriptions (#320)

docs/tools/developer-tools.mdx

@@ -29,6 +29,8 @@ A sandbox supported by SDF and Cheesecake Labs for businesses to experiment with
 
 ## Block Explorers
 
+Block explorers exist to publicly display blockchain data in an easily digestbible way. They can be browsed with an ordinary web browser, and do not require any special developer skills to use. The block explorers available for Soroban index data related to payments, accounts, deployed contracts, transaction history, and more.
+
 ### [StellarExpert](https://stellar.expert/explorer/public)
 
 Explore transactions and network activity with StellarExpert. Check stats specific to an asset code, transaction hash, account address, or ledger sequence number. Not available for Futurenet.
@@ -57,6 +59,8 @@ Auto-generated comprehensive reference documentation is available [here](https:/
 
 ## Data Indexers
 
+To power your applications, a range of data services will be available from data indexers with query interfaces. These indexers will allow you to easily store and retrieve decoded ledger data, contract event emissions, and more. You can focus more energy on making your project successful, and waste less time figuring out precisely how to get the important data from the network.
+
 ### [SubQuery](https://subquery.network/)
 
 An open-source data indexer that supports both Stellar and Soroban. SubQuery allows users to build a custom API for their dapp or smart contract and provides clean indexed data to any service. You can index ledgers, transactions, operations, and effects from Stellar and transactions and events from Soroban into your own Postgres database. Read the quick start guide here.
@@ -75,17 +79,17 @@ Mirror and indexer coming soon.
 
 ## GUIs
 
-[Laboratory](https://laboratory.stellar.org/#?network=test)
+### [Laboratory](https://laboratory.stellar.org/#?network=test)
 
 A GUI where you can use and learn about the Stellar network on the Testnet and Pubnet. You can create accounts, construct and submit transactions, and query Horizon endpoints without needing to know code.
 
-[Okashi](https://okashi.dev)
+### [Okashi](https://okashi.dev)
 
 A web GUI for building, deploying, and testing contracts.
 
 ## IDEs
 
-[Sorobix](https://sorobix.vercel.app/)
+### [Sorobix](https://sorobix.vercel.app/)
 
 An IDE where you can write, deploy, and invoke contracts on the Stellar network using Soroban.