Deal with big sample sizes and the slow down they produce in the page

When particularly fast functions are benchmarked for long, the sample size gets too large and plotly.js basically crashes or takes VERY LONG to render.

### Current work arounds:

- reduce `:time` to indirectly reduce sample size
- remove the individual graphs from the resulting HTML by hand (they are most of the cause of this happening) and maybe also the box plot (is also fed raw run times)

### Proposed solutions (might go into separate issues)

* print a warning when sample sizes exceed a certain threshold (like say 100_000)
* provide the option to split the individual graphs into separate files and then link to them
* render the box plot giving manually calculated quadrilles on the elixir side [see this thread](https://community.plot.ly/t/box-plots-manually-supply-median-and-quartiles-performance-for-alrge-sample-sizes/2459/2)