docs: fix typo.

Author: ahmedcharles

docs/guide.rst

@@ -1822,7 +1822,7 @@ Like a regular submodule, an instance can also be added without specifying a nam
 
     If a name is not explicitly specified for a submodule, one will be generated and assigned automatically. Designs with many autogenerated names can be difficult to debug, so a name should usually be supplied.
 
-Although an :class:`Instance` is not an elaboratable, as a special case, it can be returned from the :py:`elaborate()` method. This is conveinent for implementing an elaboratable that adorns an instance with an Amaranth interface:
+Although an :class:`Instance` is not an elaboratable, as a special case, it can be returned from the :py:`elaborate()` method. This is convenient for implementing an elaboratable that adorns an instance with an Amaranth interface:
 
 .. testcode::