logo: fix 0x0 px size when rendered in browser

Add width and height attribute in the top-level svg tag. This also fixes the logo not showing up in our documentation.

doc/simbricks-text-horizontal.svg

 <?xml version="1.0" encoding="UTF-8"?>
-<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 582.12 80.85">
+<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 582.12 80.85" width="582.12" height="80.85">
   <defs>
     <style>
       .cls-1 {

doc/simbricks.svg

 <?xml version="1.0" encoding="UTF-8"?>
-<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 193.87 164.94">
+<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 193.87 164.94" width="193.87" height="164.94">
   <defs>
     <style>
       .cls-1 {