Add tui-slider widget to showcase

This PR introduces a new tui-slider documentation and demo tape.
For detailed documentation please visit https://github.com/sorinirimies/tui-slider

A tui-slider.gif is included in the third-party-widgets showcasing
the widget's capabilities.

Tui Slider Features:
- 🎚️ Horizontal and Vertical sliders - Support for both orientations
- 🎨 Border styles - Multiple border style options with customizable symbols
- 🎯 Title alignment - Left, center, and right title positioning
- 📊 Value alignment - Flexible value display positioning
- 📍 Vertical positioning - Label and value positioning for vertical sliders
- 🎨 Progress bars - Use as progress indicators without handles
- 🔧 Easy to use - Minimal configuration required
- 📊 State management - Built-in state for value tracking
- ⚡ Lightweight - No complex dependencies

Author: sorinirimies

code/showcase/widget-showcase-third-party/tui-slider.tape

@@ -0,0 +1,72 @@
+# A VHS tape. See https://github.com/charmbracelet/vhs
+
+# for running against the tui-slider git repo https://github.com/sorinirimies/tui-slider
+Output "tui-slider.gif"
+Set Theme "Aardvark Blue"
+Set Width 1600
+Set Height 1000
+Set FontSize 16
+Set Padding 20
+
+Hide
+Type "cargo run --release --example horizontal"
+Enter
+Sleep 3s
+Show
+
+# Show horizontal sliders - page 1 (Standard Styles)
+Sleep 2s
+
+# Adjust some sliders quickly
+Down
+Sleep 0.3s
+Right Right Right
+Sleep 0.3s
+Down
+Sleep 0.3s
+Left Left
+Sleep 0.3s
+Down
+Sleep 0.3s
+Right Right Right
+Sleep 0.8s
+
+# Navigate to page 2 (Specialty Styles)
+Type "n"
+Sleep 1.5s
+
+# Adjust sliders on page 2
+Down
+Sleep 0.3s
+Right Right
+Sleep 0.3s
+Down
+Sleep 0.3s
+Left Left
+Sleep 1s
+
+# Exit and show vertical sliders
+Hide
+Type "q"
+Sleep 0.3s
+Type "cargo run --release --example vertical"
+Enter
+Sleep 3s
+Show
+
+# Demonstrate vertical sliders
+Sleep 1.5s
+Down
+Sleep 0.3s
+Up Up Up
+Sleep 0.3s
+Right
+Sleep 0.3s
+Down
+Sleep 0.3s
+Up Up
+Sleep 1.5s
+
+Hide
+Type "q"
+Sleep 0.3s

src/content/docs/showcase/third-party-widgets.mdx

@@ -72,6 +72,15 @@ views.
 
 ![Demo of tui-scrollview](https://vhs.charm.sh/vhs-6PuT3pdwSTp4aTvKrCBx9F.gif)
 
+## Tui-slider <LinkBadge text="Crate" href="https://crates.io/crates/tui-slider" /> <LinkBadge text="Docs" href="https://docs.rs/tui-slider" /> <LinkBadge text="GitHub" href="https://github.com/sorinirimies/tui-slider" />
+
+[`tui-slider`](https://crates.io/crates/tui-slider) is a highly customizable slider widget for both
+horizontal and vertical orientations. Perfect for music players, audio mixers, settings panels, and
+progress indicators with extensive styling options including borders, colors, symbols, and
+alignments.
+
+![tui-slider](./third-party-widgets/tui-slider.gif)
+
 ## Tui-term <LinkBadge text="Crate" href="https://crates.io/crates/tui-term" /> <LinkBadge text="Docs" href="https://docs.rs/tui-term" /> <LinkBadge text="GitHub" href="https://github.com/a-kenji/tui-term" />
 
 [`tui-term`](https://crates.io/crates/tui-term) is a pseudoterminal widget.