fix: header link (tendermint#9574)

Co-authored-by: William Banfield <[email protected]>

spec/core/data_structures.md

@@ -46,7 +46,7 @@ and a list of evidence of malfeasance (ie. signing conflicting votes).
 
 | Name   | Type              | Description                                                                                                                                                                          | Validation                                               |
 |--------|-------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------|
-| Header | [Header](#header) | Header corresponding to the block. This field contains information used throughout consensus and other areas of the protocol. To find out what it contains, visit [header] (#header) | Must adhere to the validation rules of [header](#header) |
+| Header | [Header](#header) | Header corresponding to the block. This field contains information used throughout consensus and other areas of the protocol. To find out what it contains, visit [header](#header) | Must adhere to the validation rules of [header](#header) |
 | Data       | [Data](#data)                  | Data contains a list of transactions. The contents of the transaction is unknown to Tendermint.                                                                                      | This field can be empty or populated, but no validation is performed. Applications can perform validation on individual transactions prior to block creation using [checkTx](https://github.com/tendermint/tendermint/blob/main/spec/abci/abci++_methods.md#checktx).
 | Evidence   | [EvidenceList](#evidencelist) | Evidence contains a list of infractions committed by validators.                                                                                                                     | Can be empty, but when populated the validations rules from [evidenceList](#evidencelist) apply |
 | LastCommit | [Commit](#commit)              | `LastCommit` includes one vote for every validator.  All votes must either be for the previous block, nil or absent. If a vote is for the previous block it must have a valid signature from the corresponding validator. The sum of the voting power of the validators that voted must be greater than 2/3 of the total voting power of the complete validator set. The number of votes in a commit is limited to 10000 (see `types.MaxVotesCount`).                                                                                             | Must be empty for the initial height and must adhere to the validation rules of [commit](#commit).  |