[css-text-decor-3][css-ruby] Adjust tenses.

Author: fantasai

css-ruby-1/Overview.bs

@@ -1154,10 +1154,11 @@ Ruby Text Decoration</h3>
 	in such cases it is propagated to all of the container's bases or annotations (respectively),
 	and is also drawn between them for continuity.
 
-	<p>The positions of ruby annotations may be adjusted to avoid conflicts
+	<p>The positions of ruby annotations may be adjusted
+	to avoid potential conflicts
 	with overline and underline decorations applied to the base text.
 	In the basic case of consistent font size and baseline alignment,
-	an underline or overline is to be positioned
+	an underline or overline is positioned
 	between the base level and any annotations on that side.
 
 	<p class="issue">This section needs some clarification about

css-text-decor-3/Overview.bs

@@ -798,7 +798,7 @@ Emphasis Mark Position: the 'text-emphasis-position' property</h3>
   <p>Emphasis marks are drawn exactly as if each character was
     assigned the mark as its ruby annotation text with the ruby position
     given by 'text-emphasis-position' and the ruby alignment as centered.
-    Note that this position may be adjusted if it conflicts
+    Note that this position may be adjusted if it would conflict
     with underline or overline decorations.
 
   <p>The effect of emphasis marks on the line height is the same as for