Fix UI animation typewriter (#4)

## Changes

Because strings are immutable, calling `gsub` without storing the result
is not accomplishing anything. Additionally, there was no comment
explaining what the `gsub` was doing. I fixed these issues, and also
replaced `wait` with `task.wait` to adopt modern best practice.

## Checks

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- [X] This contribution was created in whole or in part by me, and I
have the right to submit it under the terms of this repository's open
source licenses.
- [X] I understand and agree that this contribution and a record of it
are public, maintained indefinitely, and may be redistributed under the
terms of this repository's open source licenses.
- [X] To the best of my knowledge, all proposed changes are accurate.

---------

Co-authored-by: IgnisRBX <[email protected]>

content/en-us/ui/animation.md

@@ -543,7 +543,8 @@ The "typewriter" effect is ideal for `Class.TextLabel|TextLabels` that tell a st
 
    	-- Replace line break tags so grapheme loop will not miss those characters
    	displayText = displayText:gsub("<br%s*/>", "\n")
-   	displayText:gsub("<[^<>]->", "")
+    	-- Remove RichText tags since char-by-char animation will break the tags
+   	displayText = displayText:gsub("<[^<>]->", "")
 
    	-- Set translated/modified text on parent
    	guiObject.Text = displayText
@@ -552,7 +553,7 @@ The "typewriter" effect is ideal for `Class.TextLabel|TextLabels` that tell a st
    	for first, last in utf8.graphemes(displayText) do
    		index = index + 1
    		guiObject.MaxVisibleGraphemes = index
-   		wait(delayBetweenChars)
+   		task.wait(delayBetweenChars)
    	end
    end