message: specs: fix markdown lint in meta spec doc
diff: ## Go modules
  Go modules that are currently versioned:
  -```
  +
  +```text
  ./op-batcher
  ./op-bindings
  ./op-node
  @@ -12,7 +13,8 @@ Go modules that are currently versioned:
  ```
  Go modules which are not yet versioned:
  -```
  +
  +```text
  ./batch-submitter (changesets)
  ./bss-core
  ./gas-oracle (changesets)
  