The logo did not display black text when using the Github light theme in
a system configured to prefer dark mode. An alternative solution: just
make text grayish (#4e4e4e) so that it looks "ok" in both light and dark
modes.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Use an SVG based logo with embedded style that toggles title color using
media queries. The SVG logo is not exactly the same as the previous one
as I only had this version in SVG (taken from docs actually).
Note that we cannot use the method described in
https://github.blog/changelog/
2021-11-24-specify-theme-context-for-images-in-markdown/ because the
README is written in rst, not Markdown.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Gerard Marull-Paretas