docs(docs): replace markdown tables with HTML, add binary search concept page, and clean two‑pointers guide

docs/02-concepts/02-hashing.mdx

@@ -1,8 +1,6 @@
 ---
 title: 'Hashing'
 description: 'In algorithms, arrays and strings are very similar. They are both ordered collections of elements. The difference is that arrays are mutable, while strings are immutable.'
-sidebar:
-  label: Hashing
 ---