Removed Duplicate data.

Summary:
Prop for SectionList 'ItemSeperatorComponent' was repeated twice.

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  CATEGORY
[----------]        TYPE
[ CLI      ]   [-------------]      LOCATION
[ DOCS     ]   [ BREAKING    ]   [-------------]
[ GENERAL  ]   [ BUGFIX      ]   [-{Component}-]
[ INTERNAL ]   [ ENHANCEMENT ]   [ {File}      ]
[ IOS      ]   [ FEATURE     ]   [ {Directory} ]   |-----------|
[ ANDROID  ]   [ MINOR       ]   [ {Framework} ] - | {Message} |
[----------]   [-------------]   [-------------]   |-----------|

[CATEGORY] [TYPE] [LOCATION] - MESSAGE

 EXAMPLES:

 [IOS] [BREAKING] [FlatList] - Change a thing that breaks other things
 [ANDROID] [BUGFIX] [TextInput] - Did a thing to TextInput
 [CLI] [FEATURE] [local-cli/info/info.js] - CLI easier to do things with
 [DOCS] [BUGFIX] [GettingStarted.md] - Accidentally a thing/word
 [GENERAL] [ENHANCEMENT] [Yoga] - Added new yoga thing/position
 [INTERNAL] [FEATURE] [./scripts] - Added thing to script that nobody will see
-->
Closes #16872

Differential Revision: D6370787

Pulled By: hramos

fbshipit-source-id: f5b53376b6c169d96089e8706612587cc50d8669

docs/sectionlist.md

@@ -62,7 +62,6 @@ here, along with the following caveats:
 - [`sections`](docs/virtualizedlist.html#sections)
 - [`renderItem`](docs/virtualizedlist.html#renderitem)
 - [`ItemSeparatorComponent`](docs/virtualizedlist.html#itemseparatorcomponent)
-- [`ItemSeparatorComponent`](docs/virtualizedlist.html#itemseparatorcomponent)
 - [`ListEmptyComponent`](docs/virtualizedlist.html#listemptycomponent)
 - [`ListFooterComponent`](docs/virtualizedlist.html#listfootercomponent)
 SectionSeparatorComponent