Add missing datasource headers (#749)

Author: droserasprout

docs/3.datasources/1.abi_etherscan.md

@@ -4,6 +4,8 @@ description: "Etherscan is a popular Ethereum blockchain explorer. It provides a
 network: "ethereum"
 ---
 
+# Etherscan
+
 [Etherscan](https://etherscan.io/) is a popular Ethereum blockchain explorer. It provides a public API to fetch ABIs of verified contracts. DipDup can use its API to fetch ABIs for contracts being indexed.
 
 To use this datasource, add the following section in config:

docs/3.datasources/2.coinbase.md

@@ -3,6 +3,8 @@ title: "Coinbase"
 description: "A connector for Coinbase Exchange API. Provides get_candles and get_oracle_data methods. It may be useful in enriching indexes of DeFi contracts with off-chain data."
 ---
 
+# Coinbase
+
 A connector for [Coinbase Exchange API](https://docs.cloud.coinbase.com/exchange/docs/welcome). Provides `get_candles` and `get_oracle_data` methods. It may be useful in enriching indexes of DeFi contracts with off-chain data.
 
 ```yaml [dipdup.yaml]

docs/3.datasources/3.evm_node.md

@@ -4,6 +4,8 @@ description: "DipDup can connect to any EVM-compatible node via JSON-RPC. It can
 network: "ethereum"
 ---
 
+# EVM node
+
 DipDup can connect to any EVM-compatible node via JSON-RPC. It can be used as a "last mile" datasource for EVM indexes (data that is not in Subsquid Archives yet) or as a standalone datasource for handlers and hooks.
 
 Examples below show how to connect to Infura and Alchemy nodes for Ethereum mainnet indexes. You can also use your own node, but make sure it has all the necessary data (e.g. archive node).

docs/3.datasources/5.http.md

@@ -3,6 +3,8 @@ title: "HTTP"
 description: "If you need to perform arbitrary requests to APIs not supported by DipDup, use generic HTTP datasource instead of plain aiohttp requests. That way you can use the same features DipDup uses for internal requests: retry with backoff, rate limiting, Prometheus integration etc."
 ---
 
+# Generic HTTP
+
 If you need to perform arbitrary requests to APIs not supported by DipDup, use generic HTTP datasource instead of plain `aiohttp` requests. That way you can use the same features DipDup uses for internal requests: retry with backoff, rate limiting, Prometheus integration etc.
 
 ```yaml [dipdup.yaml]

docs/3.datasources/6.ipfs.md

@@ -3,6 +3,8 @@ title: "IPFS"
 description: "While working with contract/token metadata, a typical scenario is to fetch it from IPFS. DipDup has a separate datasource to perform such requests via public nodes."
 ---
 
+# IPFS
+
 While working with contract/token metadata, a typical scenario is to fetch it from IPFS. DipDup has a separate datasource to perform such requests via public nodes.
 
 ```yaml [dipdup.yaml]

docs/3.datasources/7.tezos_tzkt.md

@@ -4,6 +4,8 @@ description: "TzKT provides REST endpoints to query historical data for Tezos bl
 network: "tezos"
 ---
 
+# TzKT
+
 [TzKT](https://api.tzkt.io/) provides REST endpoints to query historical data for Tezos blockchain. Flexible filters allow to request only data needed for your application and drastically speed up the indexing process.
 
 ```yaml [dipdup.yaml]

docs/3.datasources/8.tzip_metadata.md

@@ -4,6 +4,8 @@ description: "dipdup-metadata is a standalone companion indexer for DipDup writt
 network: "tezos"
 ---
 
+# TZIP metadata
+
 [dipdup-metadata](https://github.com/dipdup-io/metadata) is a standalone companion indexer for DipDup written in Go. Configure datasource in the following way:
 
 ```yaml [dipdup.yaml]

docs/5.advanced/4.metadata-interface.md

@@ -3,12 +3,12 @@ title: "Metadata interface"
 description: "When issuing a token on Tezos blockchain, there is an important yet not enough covered aspect related to how various ecosystem applications (wallets, explorers, marketplaces, and others) will display and interact with it."
 ---
 
+# Metadata interface
+
 ::banner{type="warning"}
 This page currently describes the metadata interface only for Tezos blockchain. For EVM-based chains the process is roughly the same. We will add the EVM-specific details later.
 ::
 
-# Metadata interface
-
 When issuing a token on Tezos blockchain, there is an important yet not enough covered aspect related to how various ecosystem applications (wallets, explorers, marketplaces, and others) will display and interact with it. It's about token metadata, stored wholly or partially on-chain but intended for off-chain use only.
 
 ## Token metadata standards