docs: fix typo `qn` -> `an`

specs/glossary.md

@@ -336,7 +336,7 @@ See the [corresponding section][spec-deposit-tx-type] of the deposits spec for m
 
 [deposit-contract]: glossary.md#deposit-contract
 
-The *deposit contract* is qn [L1] contract to which [EOAs][EOA] and contracts may send [deposits]. The deposits are
+The *deposit contract* is an [L1] contract to which [EOAs][EOA] and contracts may send [deposits]. The deposits are
 emitted as log records (in Solidity, these are called *events*) for consumption by [rollup nodes][rollup-node].
 
 Advanced note: the deposits are not stored in calldata because they can be sent by contracts, in which case the calldata