Update docs.

CHANGELOG.md

@@ -4,16 +4,22 @@ Rhai Release Notes
 Version 1.13.0
 ==============
 
+This version attempts a number of optimizations that may yield small speed improvements:
+
+* Simple operators (e.g. integer arithmetic) are inlined to avoid the overhead of a function call.
+* The tokenizer uses pre-calculated tables (generated by GNU `gperf`) for keyword recognition.
+* A black-arts trick (see `Engine::black_box`) is used to prevent LLVM from optimizing hand-tuned AST node matches back into a lookup table, which messes up branch prediction on modern CPU's.
+
 Bug fixes
 ---------
 
 * Complex indexing/dotting chains now parse correctly, for example: `a[b][c[d]].e`
 * `map` and `filter` for arrays are marked `pure`. Warnings are added to the documentation of pure array methods that take `this` closures.
 * Syntax such as `foo.bar::baz` no longer panics, but returns a proper parse error.
-* Some op-assignment statements, such as `x += y` where `x` and `y` are `char`, now work correctly instead of failing silently.
 * Expressions such as `!inside` now parses correctly instead of as `!in` followed by `side`.
 * Custom syntax starting with symbols now works correctly and no longer raises a parse error.
 * Comparing different custom types now works correctly when the appropriate comparison operators are registered.
+* Some op-assignments, such as `x += y` where `x` and `y` are `char`, now work correctly instead of failing silently.
 * Op-assignments to bit flags or bit ranges now work correctly.
 
 Potentially breaking changes
@@ -30,8 +36,8 @@ Enhancements
 * The functions `min` and `max` are added for numbers.
 * Range cases in `switch` statements now also match floating-point and decimal values. In order to support this, however, small numeric ranges cases are no longer unrolled.
 * Loading a module via `import` now gives the module access to the current scope, including variables and constants defined inside.
-* Some very simple operator calls (e.g. integer add) are short-circuited to avoid the overhead of a function call, resulting in a small speed improvement.
-* The tokenizer now uses table-driven keyword recognizers generated by GNU gperf. At least _theoretically_ it should be faster...
+* Some very simple operator calls (e.g. integer add) are inlined to avoid the overhead of a function call, resulting in a small speed improvement.
+* The tokenizer now uses table-driven keyword recognizers generated by GNU `gperf`. At least _theoretically_ it should be faster...
 * The field `isAnonymous` is added to JSON functions metadata.