fix(templates): keep cross-referenced types clickable in tables

[auscaster]

Follows up @gkodinov's point on #127, which turned out to be a rendering bug rather than only a missing feature.

A parameter whose type is another documented symbol was rendered as:

| `target` | `struct [handlers](#handlers) *` | the registry to configure |

A link cannot live inside a code span, so readers saw the raw link syntax. Referenced types now keep the link and style the symbol the way linkedName already styles names elsewhere:

| `target` | struct [`handlers`](#handlers) * | the registry to configure |

Types with no reference are untouched and stay fully inline code. Return types in member summary tables link too, via the same helper, so there is one behaviour rather than two.

returnTypeShort is kept and delegates to the new typeCell helper, so templates copied from templates/cpp keep working and pick up the fix.

Covered by a real fixture case (a documented struct used as a parameter and return type) plus unit tests. Also fixed the unit test harness, which compiled its local template without noEscape and so did not match how loadTemplates compiles the real ones.

Bundles the 2.1.16 bump.