Add `docs_rs` feature flag to enable docs.rs-specific configuration,
including `--generate-link-to-definition` and logo display.

Include the feature in build scripts, editor settings, and feature
constants for consistent documentation generation.

methods

Deprecate `ShellContext` methods `filling_argument_first`,
`filling_argument`, `typing_argument`, `strip_typed_argument`, and
`get_typed_arguments` when the `picker` feature is active, as they
do not work under all `ParserStyle` settings.

Add `#![allow(deprecated)]` to the affected modules to suppress
warnings from internal usage.

BREAKING CHANGE: Remove `mingling_support` feature from arg-picker
crate. The
`EntryPicker` trait and `corebind` module are now part of the mingling
crate
directly, and `build_pattern1` is now a public method.

Picker2 replaces the original Picker1 with a two-phase (tag → pick) +
mask-bitmap architecture, decoupling argument matching from type
conversion via a composable matcher pipeline.

Architecture
- FlagMatcher — boolean flags (--verbose)
- ArgMatcher — single flag+value pairs (--name Alice)
- MultiArgMatcher — multi-value flag groups (--files a.txt b.txt)
- PositionalMatcher — positional arguments, respects `--`
- SingleMatcher — composite for Single-type Pickables

Types
- Flag (Active/Inactive) — semantic bool flag value
- String + 14 numeric types via SinglePickable trait
- Vec<T> — greedy multi-value (all SinglePickable types)
- VecUntil<T> — bounded multi-value via BoundaryCheck trait
- VecUntil<T>, pick_string, pick_numbers, pick_bool, pick_flag

Style system
- UNIX_STYLE (kebab), POWERSHELL_STYLE (Pascal), WINDOWS_STYLE (Pascal)
- naming_case auto-conversion via just_fmt integration
- Style-aware separator (= for Unix, : for PS/Windows)

Infrastructure
- internal_repeat! macro generates PickerPattern1..=32
- SinglePickable blanket impl → Pickable
- MultiPickableWithBoundary trait with greedy/bounded variants
- 151 integration tests
- Docs updated for parser feature

Move the Getting Started section above Writing with Mingling, replace
emoji decorations with plain text, remove unnecessary `use
mingling::prelude::*;` imports from code examples, and update crate
description.