chore(release): 1.2.0 (#30)

Bump 1.1.4 -> 1.2.0 across all release files (Cargo, pyproject, wasm,
conda, docs) and roll the CHANGELOG [Unreleased] section into [1.2.0].

Highlights: runtime CPU-feature dispatch (multiversion), broader wheel
coverage (linux aarch64 + musllinux + windows arm64), abi3 wheels,
Dynamic Time Warping, and indicator-specific exception types.

conda/meta.yaml

@@ -1,5 +1,5 @@
 {% set name = "ferro-ta" %}
-{% set version = "1.1.4" %}
+{% set version = "1.2.0" %}
 
 package:
   name: {{ name|lower }}