Modify the comment

Author: qryxip

.cargo/config.toml

@@ -1,2 +1,4 @@
 [build]
-rustdocflags = ["--html-in-header", "./doc/katex-header.html"] # We don't have any `normal` dependency in this package. In most cases, `package.metadata.docs.rs` is recommended.
+# This works on local `cargo doc` and on docs.rs because we don't have any `normal` dependency.
+# In most cases, `package.metadata.docs.rs` is recommended.
+rustdocflags = ["--html-in-header", "./doc/katex-header.html"]