Improve documentation for linear search algorithm

searches/linear_search.py

@@ -1,4 +1,19 @@
 """
+Linear Search Algorithm
+
+Linear search is a simple searching technique that checks each element in the collection
+sequentially until the target element is found or the collection is exhausted.
+It is also known as sequential search.
+
+Characteristics:
+- Works on both sorted and unsorted collections
+- Time complexity: O(n)
+- Space complexity: O(1)
+- Simple and reliable for small datasets
+
+For large datasets or sorted collections, binary search or other logarithmic search
+algorithms are usually more efficient.
+
 This is pure Python implementation of linear search algorithm
 
 For doctests run following command: