Fix documentation link in README; github interprets it as an image then breaks the URL
Fix documentation link in README; github interprets it as an image then breaks the URL

apoelstra/rust-secp256k1,arkpar/rust-secp256k1,apoelstra/rust-secp256k1,arkpar/rust-secp256k1,arkpar/rust-secp256k1,arkpar/rust-secp256k1,apoelstra/rust-secp256k1,apoelstra/rust-secp256k1,arkpar/rust-secp256k1