[css-text-4] Update several links

Author: xfq

css-text-4/Overview.bs

@@ -335,7 +335,7 @@ Inline breaks between boxes: the 'wrap-before'/'wrap-after' properties</h3>
 		<dd>
 			Force a <a>flex line</a> break immediately before/after the box
 			if the box is a <a>flex item</a>
-			in a <a href="https://www.w3.org/TR/css-flexbox-1/#multi_line">multi-line flex container</a>.
+			in a <a>multi-line flex container</a>.
 	</dl>
 
 	Forced line breaks on <a>inline-level</a> boxes propagate upward
@@ -1103,7 +1103,7 @@ Fullwidth Punctuation Collapsing</h4>
 	(The opposite writing mode must be used because some fonts are compressed
 	so that the characters are not square.)
 	More information on OpenType metrics can be found
-	<a href="http://www.microsoft.com/typography/otspec/baselinetags.htm#ideoembox">in the OpenType spec</a>.
+	<a href="https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags#ideoembox">in the OpenType spec</a>.
 	Note that if 水 U+6C34, 卜 U+535C, and 一 U+4E00 do not all have the same advance width,
 	the font has proportional ideographs
 	and the fullwidth advance width cannot be reliably determined by measuring glyphs.
@@ -1292,7 +1292,7 @@ Japanese Paragraph-start Conventions in CSS</h4>
 		which are distinguished by their handling of opening brackets.
 
 		<div class="figure">
-			<img src="opening-brackets-at-line-head.png"
+			<img src="images/opening-brackets-at-line-head.png"
 				width="646" height="360"
 				alt="The first scheme aligns opening brackets flush with the indent edge
 						 on the first line and with the start edge of other lines.