v0.5.0 - Githubissues

Describe your changes

Added new functions set_open_graph() and unset_open_graph() which toggle an option to automatically open a graph that has been created with save_e61(). Helpful for your workflow when perfecting graphs.

Add support in save_e61() for saving images in PDF format for compatibility with LaTeX.
Change the default alignment of plot labels to left-align and added a new argument hjust to plot_label()/mplot_label() to change the alignment.
Added the ability to add a white box around text in plot_label()/mplot_label() through geom argument.
Added y argument to add_zeroline() so you can put your zero line at values other than zero.
Added argument to scale_x_continuous_e61() to add back the first/last labels that are removed by default.
Slightly increased default size of plot labels to match size of axis text.
save_e61() now notifies you if you forget to use the theme and scale functions.

Permanent fix to the bug that was temporarily bodged in v0.4.1. Now dates can be entered as strings in plot_label() and they will be converted to dates.
Fixed a bug in scale_y_continuous_e61() that made y_top stop working and also refactored the code.
Fixed a bug in mplot_label() that didn't allow a vector of colours to be supplied.

Added a new Graph standards vignette based on masterclass materials.
Added more documentation explaining how rel_heights in mpanel_e61() works.
Miscellaneous minor documentation improvements.

Do the following before requesting a review
[x] I have written tests covering functions I have added or changed.
[x] I have run tests and they all pass.
[x] I have ensured all new functions will show up in the _pkgdown.yml file.
[x] I have updated DESCRIPTION with any new package dependencies.
[x] I have updated NEWS.md with a brief description of my changes.
[x] I have updated the package documentation with devtools::document().
[x] I have updated the package website with pkgdown::build_site_github_pages().