Allow footer links

[cjrace]

Overview of changes

Resolves #77, by adding an extra argument to the footer, allowing a vector of link text to be added, automatically generating actionLinks and IDs that can be used to control a hidden tabset.

Gone for this approach as I think it balances simplicity for the users with the functional need. As R Shiny is almost always a single page app, I assume most people would be using actionLinks to trigger a tabset shifting rather than actual href's to external pages. If we think this is a need, then I'll need to think again about the argument users can use. An alternative could be to allow users to put in any shiny tagList they deem appropriate, would be easier for us but then opens the door to more weird and wonderful stuff that might not be ideal or have the right styling.

Have added a functional example to the run_example() app too.

PR Checklist

• I have updated the documentation (if needed)
• I have added or updated tests for these changes (if applicable)
• I have tested these changes locally using devtools::check()

Reviewer instructions

1. Does it work as you'd expect?
2. Is the documentation intuitive to follow?
3. Is there enough test coverage?
4. Should we be allowing standard anchor links in this as well? (if so, then probably best to do that now before merging)
5. Do we still need the full = TRUE / FALSE option? Having poke at it a bit, I can see difference in the output code, but can't work out the difference for an end user of a dashboard? If we don't, I could try to tidy that up in this PR too?
6. Should the crown symbol be on the right? Just noticed in my screenshot it wraps underneath, which feels odd, that wasn't something I've consciously done!

[sarahmwong]

Thanks Cam!

1. Works as expected
2. documentation straightforward and easy to follow (Example in the function doesnt have an accessibility page to click into, dont htink thats a problem though as shows the layout/the cookie link functions fine
3. tests are sufficient
4. happy to only include internal shiny app links like you suggest - dont see why there would be a need for external links but could be one to monitor if anyone raises
5. Happy to get rid of full argument
6. Yes think image should be on the right if possible! Happy to pick up if this is a faff and you are heading off for xmas soon!