Strings working

[Butcher3Years]

PR Title Suggestion

Add basic std::string usage and manipulation examples

Description

This PR introduces a simple demonstration of std::string in modern C++.

What this code does:

• Shows how to create and initialize std::string objects from string literals
• Demonstrates string concatenation using += and operator+
• Passes strings efficiently to functions using const std::string& (avoids unnecessary copies)
• Uses find() to search for substrings and checks result against std::string::npos
• Prints string content using std::cout
• Briefly highlights why std::string is preferred over raw C-style strings (char* / char[])

Key learning points covered:

• Construction from const char*
• Safe and efficient string appending
• Substring search with find()
• Best practice: pass by const reference to avoid copying
• size() for getting string length (O(1))
• Comparison to old C functions (strlen, strcpy, strcat)

Why this is useful:
Helps beginners understand how modern C++ handles text safely and conveniently compared to raw character arrays.

Future improvements (optional next steps):

• Add more string methods (substr, replace, erase, etc.)
• Show move semantics and SSO (small string optimization)
• Compare performance of copy vs reference passing

Closes #