doc: update README

README.md

@@ -1,14 +1,12 @@
 ## EIP-7212 fallback `P256Verifier` contract
 
-This repo implements a gas-efficient P256 signature verifier based on [Renaud Dubois from Ledger's implementation](https://github.com/rdubois-crypto/FreshCryptoLib).
-
-Verifying a signature costs about 200k gas. Pure function, no precomputation.
-
-This implementation is a fallback contract exactly matching the proposed [EIP-7212 precompile](https://eips.ethereum.org/EIPS/eip-7212), letting us ship it as a [progressive precompile](https://ethereum-magicians.org/t/progressive-precompiles-via-create2-shadowing/).
+This repo implements a gas-efficient P256 signature verifier inspired by [Renaud Dubois's implementation](https://github.com/rdubois-crypto/FreshCryptoLib). Verifying a signature costs about 200k gas. Pure function, no precomputation.
 
 **The contract exists at a deterministic CREATE2 address. You can use it on any EVM chain. If a chain has implemented EIP-7212, you pay ~3k gas. If not, you pay ~200k gas. Either way, the contract address and results are identical.**
 
-The secp256r1 elliptic curve, aka P256, is interesting because it's a widely implemented standard. P256 is used in hardware keys such as Yubikey, Apple's Secure Element, the Android Keystore, and WebAuthn. P256 verification is especially useful for contract wallets, enabling hardware-based signing keys.
+This contract matches the proposed [EIP-7212 precompile](https://eips.ethereum.org/EIPS/eip-7212), letting us ship it as a [progressive precompile](https://ethereum-magicians.org/t/progressive-precompiles-via-create2-shadowing/).
+
+The secp256r1 elliptic curve, aka P256, is interesting because it's supported by high-quality consumer enclaves including Yubikey, Apple's Secure Enclave, the Android Keystore, and WebAuthn. P256 verification is especially useful for contract wallets, enabling hardware-based signing keys.
 
 ## Development
 
@@ -18,11 +16,25 @@ Run `foundryup` to ensure you have the latest foundry. Then,
 git clone --recurse-submodules [email protected]:daimo-eth/eip-7212
 cd eip-7212
 forge test --via-ir -vv
+```
+
+This runs test input and output handling as well as all applicable Wycheproof
+test vectors, covering a range of edge cases.
 
-# Coverage. Install the recommended extension to view.
+<details>
+<summary>Code coverage</summary>
+Install the recommended extension to view line-by-line test coverage.
+To regenerate coverage:
+
+```
 forge coverage --via-ir --ir-minimum --report lcov
 ```
 
+</details>
+
+<details>
+<summary>Test vectors</summary>
+
 To regenerate test vectors:
 
 ```
@@ -43,3 +55,5 @@ forge test --via-ir -vv
 
 # In future, execution spec and clients can test against the same clean vectors
 ```
+
+</details>