[css-grid] Change heading from 'Error Handling' to 'Conflict Handling'.

Author: tabatkins

css-grid/Overview.bs

@@ -2195,7 +2195,7 @@ Line-based Placement: the 'grid-row-start', 'grid-column-start', 'grid-row-end',
 	</div>
 
 <h4 id='grid-placement-errors'>
-Grid Placement Error Handling</h4>
+Grid Placement Conflict Handling</h4>
 
 	If 'grid-row-end'/'grid-column-end' specifies a line at or before that specified by 'grid-row-start'/'grid-column-start',
 	it instead contributes nothing.

css-grid/Overview.html

@@ -214,7 +214,7 @@ <h2 class="no-num no-toc no-ref heading settled heading" id=contents><span class
 			<li><a href=#common-uses-auto-sizing><span class=secno>8.1.5</span>  Auto Sizing Subgrids</a></ul>
 		<li><a href=#line-placement><span class=secno>8.2</span>  Line-based Placement: the <span class=property data-link-type=propdesc title=grid-row-start>grid-row-start</span>, <span class=property data-link-type=propdesc title=grid-column-start>grid-column-start</span>, <span class=property data-link-type=propdesc title=grid-row-end>grid-row-end</span>, and <span class=property data-link-type=propdesc title=grid-column-end>grid-column-end</span> properties</a>
 			<ul class=toc>
-			<li><a href=#grid-placement-errors><span class=secno>8.2.1</span>  Grid Placement Error Handling</a></ul>
+			<li><a href=#grid-placement-errors><span class=secno>8.2.1</span>  Grid Placement Conflict Handling</a></ul>
 		<li><a href=#placement-shorthands><span class=secno>8.3</span>  Placement Shorthands: the <span class=property data-link-type=propdesc title=grid-column>grid-column</span>, <span class=property data-link-type=propdesc title=grid-row>grid-row</span>, and <span class=property data-link-type=propdesc title=grid-area>grid-area</span> properties</a>
 		<li><a href=#abspos-items><span class=secno>8.4</span>  Absolutely-positioned Grid Items</a></ul>
 	<li><a href=#alignment><span class=secno>9</span>  Alignment</a>
@@ -2267,7 +2267,7 @@ <h3 class="heading settled heading" data-level=8.2 id=line-placement><span class
 	</div>
 
 <h4 class="heading settled heading" data-level=8.2.1 id=grid-placement-errors><span class=secno>8.2.1 </span><span class=content>
-Grid Placement Error Handling</span><a class=self-link href=#grid-placement-errors></a></h4>
+Grid Placement Conflict Handling</span><a class=self-link href=#grid-placement-errors></a></h4>
 
 <p>If <a class=property data-link-type=propdesc href=#propdef-grid-row-end title=grid-row-end>grid-row-end</a>/<a class=property data-link-type=propdesc href=#propdef-grid-column-end title=grid-column-end>grid-column-end</a> specifies a line at or before that specified by <a class=property data-link-type=propdesc href=#propdef-grid-row-start title=grid-row-start>grid-row-start</a>/<a class=property data-link-type=propdesc href=#propdef-grid-column-start title=grid-column-start>grid-column-start</a>,
 	it instead contributes nothing.</p>