docs(docs): add solution documentation for Container With Most Water and Is Subsequence

docs/solutions/(two-pointers)/392-is-subsequence.mdx

@@ -0,0 +1,44 @@
+---
+title: '392. Is Subsequence'
+description: Given two strings s and t, return true if s is a subsequence of t, or false otherwise
+sidebar:
+  label: 'Is Subsequence'
+  badge: 'Easy'
+---
+
+<Badge variant="accent">Two Pointers</Badge>
+
+::::warning
+Suppose there are lots of incoming s, say s1, s2, ..., sk where k >= 10^9, and you want to check one by one to see if t has its subsequence. In this scenario, how would you change your code?
+::::
+
+### Example 1:
+- Input: `s = "abc", t = "ahbgdc"`
+- Output: `true`
+
+### Example 2:
+- Input: `s = "axc", t = "ahbgdc"`
+- Output: `false`
+
+### Constraints:
+
+- `0 <= s.length <= 100`
+- `0 <= t.length <= 10^4`
+- `s` and `t` consist only of lowercase English letters.
+
+## Solution
+
+```py
+class Solution:
+    def isSubsequence(self, s: str, t: str) -> bool:
+        if len(s) > len(t):
+            return False
+
+        i, j = 0, 0
+        while i < len(s) and j < len(t):
+            if s[i] == t[j]:
+                i += 1
+            j += 1
+
+        return i == len(s)
+```