Document that all table styles are inherited (twbs#20699)

Author: mdo

docs/content/tables.md

@@ -14,7 +14,7 @@ Due to the widespread use of tables across third-party widgets like calendars an
 
 ## Examples
 
-Using the most basic table markup, here's how `.table`-based tables look in Bootstrap.
+Using the most basic table markup, here's how `.table`-based tables look in Bootstrap. **All table styles are inherited in Bootstrap 4**, meaning any nested tables will be styled in the same manner as the parent.
 
 {% example html %}
 <table class="table">