feat(unicode): add UniCode demo for exploring Unicode character ranges

What
- Introduced UniCode class to demonstrate working with Unicode characters in Java.
- Prints:
  - Greek and Coptic characters from U+0370 to U+03FF.
  - Devanagari characters from U+0900 up to U+0970.
- Declared a sample char `x = 0x03c8` (Greek letter psi).

Why
- Showcases how Java `char` type supports Unicode (16-bit, UTF-16).
- Demonstrates direct use of Unicode code points via hexadecimal literals.
- Provides practical insight into multilingual text handling in Java.

How to use
- Run UniCode.
- Output will display:
  1. Greek letters and symbols sequentially.
  2. Devanagari script characters sequentially.

Real-life applications
- Rendering multilingual UIs (Greek, Hindi, etc.).
- Handling internationalization (i18n) and localization (l10n).
- Generating or parsing Unicode text for fonts, editors, or compilers.
- Learning how Unicode blocks map to Java `char`.

Notes
- Java `char` represents UTF-16 code units (not full Unicode code points above U+FFFF).
- For supplementary characters (outside BMP), use `int` and methods like `Character.toChars()`.
- The loop with `0x0900` to `0x970` prints the Devanagari block, but should use `0x0970` (typo fix recommended).

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section26DateandTimeAPI/src/UniCode.java

@@ -4,8 +4,31 @@ public static void main(String args[]) {
 
         for(char c = 0x0370; c <= 0x03FF; c++)
             System.out.print(c + " ");
-
         for(char b = 0x0900; b <= 0x970; b++)
             System.out.println(b);
     }
 }
+
+/*
+1. Unicode Basics:
+   - Java internally `char` ko Unicode (16-bit) ke form me store karta hai.
+   - Iska matlab hai ki Java directly **multi-language support** deta hai (Greek, Hindi, Chinese… sab).
+
+2. Code Explanation:
+   - `char x = 0x03c8;`
+     → Unicode hexadecimal `0x03c8` ek Greek letter (ψ) ko represent karta hai.
+   - `for (char c = 0x0370; c <= 0x03FF; c++)`
+     → Loop karega **Greek Unicode block (U+0370 to U+03FF)** ke saare characters print karne ke liye.
+   - `for (char b = 0x0900; b <= 0x0970; b++)`
+     → Loop karega Devanagari Unicode block (U+0900 to U+0970)
+     ke saare characters print karne ke liye (jaise: अ, आ, क, ख…).
+
+3. Output Samajhne Layak:
+   - Pehle loop Greek alphabets dikhayega.
+   - Dusre loop Hindi/Devanagari script ke letters print karega.
+
+4. Quick Recap:
+   ✔ Java ka `char` = Unicode support → ek character = 16-bit code point.
+   ✔ Unicode hexadecimal values likh ke alag-alag scripts print kar sakte ho.
+   ✔ Is program se tum Greek + Hindi alphabets console pe dekh paoge.
+*/