docs(eager-loading.md): fix typo (sequelize#13161)

Author: gabrieluizramos

docs/manual/advanced-association-concepts/eager-loading.md

@@ -1,6 +1,6 @@
 # Eager Loading
 
-As briefly mentioned in [the associations guide](assocs.html), eager Loading is the act of querying data of several models at once (one 'main' model and one or more associated models). At the SQL level, this is a query with one or more [joins](https://en.wikipedia.org/wiki/Join_(SQL)).
+As briefly mentioned in [the associations guide](assocs.html), eager Loading is the act of querying data of several models at once (one 'main' model and one or more associated models). At the SQL level, this is a query with one or more [joins](https://en.wikipedia.org/wiki/Join_\(SQL\)).
 
 When this is done, the associated models will be added by Sequelize in appropriately named, automatically created field(s) in the returned objects.