DOCS-1842 - Add persona-based learning paths to training FAQ

[mafsumo]

Purpose of this pull request

This pull request adds a "Role-based learning paths" section to the Training and Certifications FAQ, covering the 8 new persona-driven learning paths (Security: SOC/Security Analyst, Cloud Security Architect, SOC Administrator; Observability: DevOps/IT Contributor, Log Analyst/SRE, IT Ops Leader, System Administrator, DevOps Leader). Each path links to its guided path in the Learning Portal and a downloadable PDF handout, so Digital CS and PS outreach can point customers to a specific role-based path instead of a generic course list.

Select the type of change

• Minor Changes - Typos, formatting, slight revisions
• Update Content - Revisions, updating sections
• New Content - New features, sections, pages, tutorials
• Site and Tools - .clabot, version updates, maintenance, dependencies, new packages for the site (Docusaurus, Gatsby, React, etc.)

Ticket (if applicable)

https://sumologic.atlassian.net/browse/DOCS-1842

[kimsauce]

In light mode, two button styles are too close in weight. "Start path" (filled grey) and "Download PDF" (outline) read as almost the same emphasis, so the visual distinction does no work. "Start path" is the primary action per row — let it carry a bit more weight (e.g. keep it as button--secondary, and drop "Download PDF" to a plain text link with a download icon, or button--link). That also de-clutters the table.

[kimsauce]

Repeated link text ("Start path" / "Download PDF" ×8) gives screen-reader users no context. Add aria-label="Start the SOC/Security Analyst path" etc.

[mafsumo]

Thanks for the feedback, Kim. Both items are addressed: "Start path" keeps its filled secondary button as the primary action, and "Download PDF" now uses Infima's plain button--link style so the two read as distinct again. I also added a role-specific aria-label to every link, start and download, so screen readers get the role name instead of hearing "Start path" or "Download PDF" sixteen times.