Manual tweaks on all SVGs

* Gives a consistent header to all images
* Makes future changes easier to see
* Some images slightly smaller
* Some images use SVG2 features (`href`)
* Most images smaller or the same size
* A few images slightly larger

images/svg/keybase.svg

@@ -1 +1,6 @@
-<svg fill="#282827" viewBox="0 0 512 512" xmlns="http://www.w3.org/2000/svg" aria-label="Keybase" role="img"><rect fill="#fff" height="512" rx="15%" width="512"/><g fill="#282828"><path d="m201 80 22-31 18 10c-9 18-8 24-8 26 8-3 81 10 59 80 0 0 44 12 76 57 29 39 11 104-57 84-58-17-111-13-177 40l32-81-79 102c-3-99 10-140 79-190-23-1-41-18-40-38l2-27c1-19 17-35 37-34 1-1 36 1 36 2zm36 96c-5-6-15 1-9 7l21 25-10 8c-2 2-3 5-1 7l2 3c3 3 6 0 6 0l10-9 10 10-22 17c-2 2-2 5-1 7l9 11c2 2 5 2 7 1l22-17 6 7c5 6 14-1 9-7zm-50-70-21-2c-5 0-10 4-11 9l-1 27c0 6 4 10 9 10l16 1c-1-6 4-36 8-45z"/><circle cx="215" cy="348" r="14"/><circle cx="298" cy="348" r="14"/></g></svg>
+<svg xmlns="http://www.w3.org/2000/svg"
+aria-label="Keybase" role="img"
+viewBox="0 0 512 512"><rect
+width="512" height="512"
+rx="15%"
+fill="#fff"/><g fill="#282828"><path d="m201 80 22-31 18 10c-9 18-8 24-8 26 8-3 81 10 59 80 0 0 44 12 76 57 29 39 11 104-57 84-58-17-111-13-177 40l32-81-79 102c-3-99 10-140 79-190-23-1-41-18-40-38l2-27c1-19 17-35 37-34 1-1 36 1 36 2zm36 96c-5-6-15 1-9 7l21 25-10 8c-2 2-3 5-1 7l2 3c3 3 6 0 6 0l10-9 10 10-22 17c-2 2-2 5-1 7l9 11c2 2 5 2 7 1l22-17 6 7c5 6 14-1 9-7zm-50-70-21-2c-5 0-10 4-11 9l-1 27c0 6 4 10 9 10l16 1c-1-6 4-36 8-45z"/><circle cx="215" cy="348" r="14"/><circle cx="298" cy="348" r="14"/></g></svg>