[css-overflow-3] Editorial improvements

Remove redundant text, and fix typo.

Author: frivoal

css-overflow-3/Overview.bs

@@ -1091,18 +1091,7 @@ Once it is sufficiently stable in this specification,
 		<dd>
 
 			If the box has more content than can fit,
-			the excess content is handled according to the usual rules:
-
-			If the box is not a [=fragmentation container=]
-			or if it is the last [=fragmentation container=] in a [=fragmentation context=]
-			which does not automatically generate more as needed (for example the last region in a region chain, see [[CSS-REGIONS-1]]),
-			content that doesn't fit into the box overflows,
-			as specified by the 'overflow' property.
-
-			Otherwise (i.e. the box is a non-last fragmentation container),
-			the remainer of the [=fragmented flow=] after the [=fragmentation break=] (if any)
-			is flowed to the next [=fragmentation container=] in the [=fragmentation context=].
-			The 'overflow' property continues to govern how to handle the contents of a box that extend outside one of that box’s edges
+			the excess content is handled according to the usual rules.
 
 		<dt><dfn>discard</dfn>
 		<dd>
@@ -1123,7 +1112,7 @@ Once it is sufficiently stable in this specification,
 			similar to if it were ''display: none'':
 			* Just as the content is visually hidden, it is not made available for speech rendering
 			* It does not allow user interaction
-			* Issue(2970): Mae sure effects on OM are well defined
+			* Issue(2970): Make sure effects on OM are well defined
 			* [=Positioned=] elements whose static position is in the discarded content are not rendered.
 
 				Issue(2971): Are we sure about that?