[css-position] Fix some minor typos and grammatical issues

Author: gilmoreorless

css-position/Overview.bs

@@ -435,7 +435,7 @@ Relative positioning</h3>
   A relatively positioned box keeps its <a>normal flow</a> size, including
   line breaks and the space originally reserved for it.
 
-  A relatively positioned box establishes a new a new <a>containing block</a> for
+  A relatively positioned box establishes a new <a>containing block</a> for
   absolutely positioned descendants. (This is a common use of relatively positioned
   boxes.) The section on <a>containing blocks</a>
   explains when a relatively positioned box establishes a new <a>containing block</a>.
@@ -516,7 +516,7 @@ Sticky positioning</h3>
   A stickily positioned box keeps its <a>normal flow</a> size, including  line
   breaks and the space originally reserved for it.
 
-  A stickily positioned box establishes a new a new <a>containing block</a> for
+  A stickily positioned box establishes a new <a>containing block</a> for
   absolutely positioned descendants, just as relative positioning does. The section
   on <a>containing blocks</a> explains when a
   stickily positioned box establishes a new <a>containing block</a>.
@@ -618,11 +618,6 @@ Sticky positioning</h3>
     to "flow root," since that's the closest thing currently specced somewhere,
     but this is not optimal.
   </p>
-<div class=example>
-  The following example is the same as the previous one, but now it is explained:
-
-  <pre>EM { font-style: italic }</pre>
-</div>
 <!-- End section: Sticky positioning  -->
 
 <h3 id="abs-pos">
@@ -767,7 +762,7 @@ Choosing a positioning scheme: 'position' property</h3>
       <li>
       table-row-group, table-header-group, table-footer-group and table-row offset
       relative to its normal position within the table. If table-cells span
-      multiple rows, only the cells originating in the <a>relative positioned</a> row is
+      multiple rows, only the cells originating in the <a>relative positioned</a> row are
       offset.
 
       <li>
@@ -989,7 +984,7 @@ Box offsets: 'top', 'right', 'bottom', 'left'</h3>
 <h3 id="logical-box-offsets-beaso">
 Logical box offsets: 'offset-before', 'offset-end', 'offset-after' and 'offset-start'</h3>
 
-  Logical offset properties allow for offseting positioned boxes based on the
+  Logical offset properties allow for offsetting positioned boxes based on the
   'writing-mode' and 'direction' properties. When both the physical property and
   equivalent logical property (based on 'writing-mode' and 'direction') are
   specified the physical property computes to the computed value of the corresponding
@@ -1015,10 +1010,10 @@ Logical box offsets: 'offset-before', 'offset-end', 'offset-after' and 'offset-s
   margin edge is offset from the corresponding physical reference edge of the box’s
   <a>containing block</a>.
 
-  The partiucular physical reference edge that is used when offsetting is based
+  The particular physical reference edge that is used when offsetting is based
   on the 'writing-mode' and 'direction' properties.
 
-  The combination of the 'writing-mode' and 'direction' properties determine the
+  The combination of the 'writing-mode' and 'direction' properties determines the
   appropriate physical reference edge for offsetting.
 
   The table below shows logical offset properties (per 'writing-mode' and