* move `searx/static/themes/simple/img/searxng.svg` to `src/brand/searxng.svg`
* README.rst can use it without a reference to a theme.
* the simple theme can create `searx/static/themes/simple/img/searxng.png` using
the svg2png task
Suggested-by: @dalf https://github.com/searxng/searxng/pull/561#issuecomment-981747902
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
Folder src/brand is intended to place logo, wordmark and more in. This commit
moves the origin (source) of searxng-wordmark.svg from the simple theme into
this folder
About the new created src/ folder:
On the long term we can move all the files from static/themes/<name>/src/* into
a src/themes/<name>/* folder.
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>