Docs: Connector pages need reformatting and image updates

[kiran1287]

Problem

Connector documentation under v2.0.x-SNAPSHOT/connectors/ has fallen behind Collate's ai-2.0 docs in several ways:

1. Overview pages use an outdated template

Every connector overview page is built from a generic MetadataIngestionUi/Steps component pattern, rather than the fully-written-out single-page format used in Collate's ai-2.0 docs. This makes the OSS docs visually and structurally inconsistent with the reference implementation, and harder to maintain since content is split across shared generic snippets instead of being explicit per connector.

2. Four connectors are missing entirely

IOMETE, Google Drive, Omni, and Prefect have no documentation under v2.0.x-SNAPSHOT/connectors/ at all — no overview page, no yaml.mdx, no troubleshooting.mdx, no docs.json entry, and no card on the connectors landing page or homepage integration grid.

3. Per-connector screenshots are stale

Metadata Ingestion screenshots (Select Service / Add New Service Name / Configure Service Connection) for existing connectors were carried over from pre-2.0 assets rather than the current ai-2.0 reference images. Affects 256 images across all 10 connector categories.

4. Collate-only content has leaked into OSS docs

20 database connector pages contain a "Hybrid Ingestion Runner" tip block referencing docs.getcollate.io — a Collate-only concept with a link to Collate's own docs site, inapplicable to OpenMetadata OSS.

5. Ingestion guide pages are out of date with actual product behavior

• Lineage/Usage workflow pages document an old wizard-style UI instead of the current Agent-based UI.
• Spark Lineage only documents the deprecated custom openmetadata-spark-agent.jar, with no mention of the native OpenLineage Spark listener integration now supported (POST /api/v1/openlineage/lineage).
• Export Lineage only documents CSV export; PNG and PDF export are undocumented.
• Unity Catalog's incremental extraction page states an explicit GRANT SELECT is required on information_schema.tables, which contradicts Databricks' own documentation.

6. Writing-style checklist violations

Latin abbreviations (i.e./e.g./etc.), arrow characters in UI navigation paths (→ instead of **X** > **Y**), and headings with no body sentence before the next heading/image/code block, scattered across connector pages.

7. No connector search/filter on the v2.0.x-SNAPSHOT connectors page

Unlike Collate's ai-2.0 connectors page, v2.0.x-SNAPSHOT/connectors.mdx has no way to search or filter the full connector list.

Tracking

Addressed by #389.