Add Breadcrumbs documentation and samples

[simeonoff]

Task type

• New topic / component documentation
• Update existing topic (new release, API change, new feature)
• Add missing platform variant (Angular / React / WebComponents / Blazor)
• Improve existing content (clarity, examples, structure)
• Add or update code samples
• Other

Platform(s)

• Angular
• React
• WebComponents
• Blazor
• All platforms

Description

Prepare documentation and live samples for the Breadcrumbs components, IgcBreadcrumbsComponent / <igc-breadcrumbs> and IgcBreadcrumbComponent / <igc-breadcrumb>.

Create a topic in the Menus navigation section that covers:

• installation, registration of the Breadcrumbs components, and basic usage;
• composing a trail from <igc-breadcrumb> items inside <igc-breadcrumbs>;
• marking the active item with current and its aria-current="page" behavior;
• setting a shared separator through the container's separator property;
• overriding separators per item through the separator slot;
• adding content through the default, prefix, and suffix slots;
• accessible structure using a labeled <nav> landmark around the breadcrumb list;
• wrapping/long-trail and RTL behavior;
• styling with the exposed CSS parts and CSS custom properties.

Add corresponding runnable samples to IgniteUI/igniteui-wc-examples and embed them in the topic. The sample set should include basic usage plus examples for custom separators, prefix/suffix content, long or responsive trails, and styling.

Acceptance criteria

• The documentation and samples are based on the final API merged from feat: Added breadcrumb container and breadcrumbs elements igniteui-webcomponents#1881.
• A new Breadcrumbs overview topic is added to the xplat documentation with complete SEO/LLM frontmatter.
• The topic is visible for all platforms in the Menus navigation section and is marked as new.
• Getting Started shows installation, import/registration, and minimal <igc-breadcrumbs> / <igc-breadcrumb> usage.
• The topic documents current-page state, separators, slots, accessible markup, wrapping/RTL behavior, and styling.
• Runnable platform samples are added to IgniteUI/igniteui-wc-examples (et. al), including basic, custom-separator, prefix/suffix, long/responsive, and styling scenarios.
• Every embedded sample loads successfully in the platform docs and exposes its source in the live editor.
• API links/references resolve to both IgcBreadcrumbsComponent and IgcBreadcrumbComponent and their public members.
• The topic and samples are published only after the component is available in a released igniteui-webcomponents package.
• Platform documentation generation/build, Markdown linting, spellcheck, and link checks pass.

Related resources

• Component pull request (not yet merged): feat: Added breadcrumb container and breadcrumbs elements igniteui-webcomponents#1881
• Breadcrumbs container source: https://github.com/IgniteUI/igniteui-webcomponents/blob/rkaraivanov/breadcrumbs/src/components/breadcrumb/breadcrumbs.ts
• Breadcrumb item source: https://github.com/IgniteUI/igniteui-webcomponents/blob/rkaraivanov/breadcrumbs/src/components/breadcrumb/breadcrumb.ts
• Storybook examples source: https://github.com/IgniteUI/igniteui-webcomponents/blob/rkaraivanov/breadcrumbs/stories/breadcrumbs.stories.ts
• WAI-ARIA Breadcrumb Pattern: https://www.w3.org/WAI/ARIA/apg/patterns/breadcrumb/