Fix logo (#321)

* Fix logo

* Align html

Author: gdalle

README.md

@@ -1,4 +1,9 @@
-# BenchmarkTools.jl <picture> <source media="(prefers-color-scheme: dark)" srcset="./docs/build/assets/logo-dark.svg" width="100" height="100"> <img alt="BenchmarkTools logo" src="./docs/build/assets/logo.svg" width="100" height="100"> </picture>
+# BenchmarkTools.jl
+
+<picture>
+<source media="(prefers-color-scheme: dark)" srcset="./docs/build/assets/logo-dark.svg" width="100" height="100">
+<img alt="BenchmarkTools logo" src="./docs/build/assets/logo.svg" width="100" height="100">
+</picture>
 
 [![][docs-stable-img]][docs-stable-url]
 [![][docs-dev-img]][docs-dev-url]