Function defintions should not include tooltips and links

Hello,

When defining a new functions with e.g.: `myfunc(a, b) = a + b`, the `myfunc` should not be underlined with a tooltip, if it happens that an internal `myfunc` already exist in the package (by internal I mean non-exported but still documented, since it's only for the developers).

See the example here: https://juliacontrol.github.io/ModelPredictiveControl.jl/stable/public/sim_model/#c-98447a37.

The `f!` and `h!` functions should not be underlined since I'm defining new functions, and the internal `ModelPredictiveControl.f!` and `ModelPredictiveControl.h!` functions are irrelevant here. Note that the issue affects both the terse (see above) and non-terse (with `function` keyword) version of function definitions.

Reproduce the behavior using the linked ModelPredictiveControl.jl example and compare terse and non-terse Julia function definitions. Trace how function definitions are handled, then verify that newly defined names do not receive tooltips or links while unrelated internal functions remain unaffected.

Written by the indexing model from the issue text.