docs(docs): restructure documentation directories and remove placeholder study decks

docs/guides/(algorithms)/02-two-pointers.mdx

@@ -13,8 +13,3 @@ This page is a scaffold. Notes, canonical problems, and template code are not wr
 
 
 
-## Study deck
-
-Drill the essentials — click the deck, then use the arrow keys.
-
-<StudyDeck deck="two-pointers" />

docs/guides/(algorithms)/03-prefix-sum.mdx

@@ -7,8 +7,3 @@ description: 'Precomputed cumulative state for O(1) range queries.'
 This page is a scaffold. Notes, canonical problems, and template code are not written yet.
 :::
 
-## Study deck
-
-Drill the essentials — click the deck, then use the arrow keys.
-
-<StudyDeck deck="prefix-sum" />

docs/guides/(algorithms)/04-sliding-window.mdx

@@ -7,8 +7,4 @@ description: 'Two pointers plus incremental state between them.'
 This page is a scaffold. Notes, canonical problems, and template code are not written yet.
 :::
 
-## Study deck
 
-Drill the essentials — click the deck, then use the arrow keys.
-
-<StudyDeck deck="sliding-window" />

docs/guides/(algorithms)/05-binary-search.mdx

@@ -29,8 +29,4 @@ Random access in this context means that you can access an element at any index
 :::
 
 
-## Study deck
 
-Drill the essentials — click the deck, then use the arrow keys.
-
-<StudyDeck deck="binary-search" />

docs/guides/(data-structures)/01-arrays-and-strings.mdx

@@ -63,9 +63,3 @@ Random access in this context means that you can access an element at any index
 </Columns>
 
 
-
-## Study deck
-
-Drill the essentials — click the deck, then use the arrow keys.
-
-<StudyDeck deck="arrays-and-strings" />

docs/guides/(data-structures)/02-hashing.mdx

@@ -28,9 +28,3 @@ Appending to the end of a list is amortized O(1) time complexity. This means tha
 Random access in this context means that you can access an element at any index in constant time.
 :::
 
-
-## Study deck
-
-Drill the essentials — click the deck, then use the arrow keys.
-
-<StudyDeck deck="hashing" />