Update index.html (#2290)

recognise -> recognize

files/en-us/related/imsc/index.html

@@ -113,7 +113,7 @@ <h2 id="Tutorials">Tutorials</h2>
  <dt><a href="/en-US/docs/Related/IMSC/Subtitle_placement">Subtitle placement in IMSC</a></dt>
  <dd>IMSC allows the author to precisely control the position of subtitles, such that the text is positioned next to the speaker or to avoid obscuring an important content in your video. Learn how to define a subtitle region and how to define its width and height.</dd>
  <dt><a href="/en-US/docs/Related/IMSC/Namespaces">Namespaces in IMSC</a></dt>
- <dd>This article covers the subject of XML namespaces, giving you enough information to recognise their usage in IMSC, and be able to use it effectively.</dd>
+ <dd>This article covers the subject of XML namespaces, giving you enough information to recognize their usage in IMSC, and be able to use it effectively.</dd>
  <dt><a href="/en-US/docs/Related/IMSC/Timing_in_IMSC">Timing in IMSC</a></dt>
  <dd>When building an IMSC document, each defined piece of text must include timing information to specify when it should appear. There are multiple ways to describe when a subtitle should start and stop displaying, with pros and cons to each method.</dd>
  <dt><a href="/en-US/docs/Related/IMSC/Mapping_video_time_codes_to_IMSC">Mapping video time codes to IMSC</a></dt>