update default chunking methods in README and SVG diagrams

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: avok

README.md

@@ -66,9 +66,9 @@ All metrics are implemented in [`metrics.py`](src/adaptive_chunking/metrics.py)
 
 | Method | Description |
 |--------|-------------|
-| **Recursive** | Splits on a hierarchy of separators (paragraphs → sentences → characters) with configurable merge modes and overlap |
-| **Sentence** | Groups consecutive sentences (NLTK, SpaCy, or Stanza) into fixed-size chunks |
-| **Semantic** | Detects topic shifts via embedding similarity between consecutive sentences |
+| **Recursive (merge-to-size)** | Splits on a hierarchy of separators then merges small chunks up to a target size |
+| **Recursive (merge-small-only)** | Same recursive split but only merges undersized chunks, preserving natural boundaries |
+| **Page** | Splits on page breaks |
 | **LLM Regex** | Asks an LLM to generate document-specific regex split patterns |
 
 The recursive splitter lives in [`splitters.py`](src/adaptive_chunking/splitters.py); the others are in [`paper/splitters.py`](src/adaptive_chunking/paper/splitters.py). You can register any callable that takes text and returns a list of chunks.