Fixed a typo and the "filetype" parameter description on the API page.
Fixed a typo and the "filetype" parameter description on the API page.

ProjectSidewalk/SidewalkWebpage,ProjectSidewalk/SidewalkWebpage,ProjectSidewalk/SidewalkWebpage,ProjectSidewalk/SidewalkWebpage,ProjectSidewalk/SidewalkWebpage,ProjectSidewalk/SidewalkWebpage