Add brotli logo (#845)

Co-authored-by: Eugene Kliuchnikov <eustas@chromium.org>
diff --git a/docs/brotli.svg b/docs/brotli.svg
new file mode 100644
index 0000000..1791c0b
--- /dev/null
+++ b/docs/brotli.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><g transform="translate(256,256)scale(24)rotate(15)" style="fill:#fff;"><circle style="fill:#ea3" r="10"/><ellipse rx="2" ry="8"/><ellipse cx="5" rx="1" ry="4"/><ellipse cx="-5" rx="1" ry="4"/></g></svg>
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