docs: update README with improved formatting and structured content

- Reformatted the README for better readability with consistent indentation and line breaks
- Restructured course outline with clear lesson numbering and descriptions
- Added detailed getting started instructions with step-by-step setup process
- Included repository layout diagram showing file organization
- Enhanced requirements section with clearer dependency structure
- Added what to expect section outlining project characteristics and learning approach

prompt.md

@@ -51,28 +51,28 @@ Use this exact section order:
 18) (Optional) Save/Load & CLI Interface
 
 === Constraints & Defaults
-- Dataset: do NOT auto-download. Expect a local `data.txt`. If missing, include a tiny built-in fallback sample so scripts still run.
+- Dataset: do NOT auto-download. Expect a local data.txt. If missing, include a tiny built-in fallback sample so scripts still run.
 - Encoding: UTF-8. Normalize newlines to "\n" for consistency.
-- Seeds: demonstrate reproducibility (`random`, `numpy`, `torch`).
+- Seeds: demonstrate reproducibility (random, numpy, torch).
 - Dependencies:
-  * Stdlib only until Lesson 9;
-  * NumPy in Lessons 8–10;
-  * PyTorch from Lesson 11 onward.
+  * Stdlib only until Lesson 9
+  * NumPy in Lessons 8–10
+  * PyTorch from Lesson 11 onward
 - Training defaults (for Lessons 13+):
-  * Batch size ~32, block size ~128, AdamW(lr=3e-4).
-  * Brief note on early stopping when val loss plateaus.
+  * Batch size ~32, block size ~128, AdamW(lr=3e-4)
+  * Brief note on early stopping when val loss plateaus
 - Inference defaults:
-  * Start with greedy; then temperature=0.8, top-k=50.
+  * Start with greedy; then temperature=0.8, top-k=50
 - Keep code clean: type hints where helpful; no frameworks beyond NumPy/PyTorch; no external data loaders.
 
 === Lesson 1 Specifics
 For Lesson 1, include:
-- Module docstring with Usage example (`python 01_read_text.py`).
-- Functions: `load_text(path: Optional[Path])`, `normalize_newlines(text: str)`,
-  `make_preview(text: str, n_chars: int = 200)`, `report_stats(text: str)`, `main()`.
-- At least one doctest per function where reasonable.
-- Fallback text snippet if `data.txt` isn’t found.
-- Output: total chars, unique chars, 200-char preview with literal "\n".
+- Module docstring with Usage example (python 01_read_text.py)
+- Functions: load_text(path: Optional[Path]), normalize_newlines(text: str),
+  make_preview(text: str, n_chars: int = 200), report_stats(text: str), main()
+- At least one doctest per function where reasonable
+- Fallback text snippet if data.txt isn’t found
+- Output: total chars, unique chars, 200-char preview with literal "\n"
 
 === Delivery
 - Start with a short “How to use this repo” preface and a file tree suggestion.