update README

README.md

@@ -1,6 +1,9 @@
 # Idris-multihash
 
-Multihash implementation for Idris. It depends on the [idris-bytes](https://github.com/ziman/idris-bytes) library
+[Multihash](https://github.com/multiformats/multihash/) implementation for Idris. 
+
+Using the [idris-bytes](https://github.com/ziman/idris-bytes) library you can encode and decode types using the 
+`IMultihash` interface.
 
 ## How to install
 
@@ -33,6 +36,43 @@ idris -p idris-multihash
 The `Data.Multihash` import gives you access to the Multihash error type and to `decode` and
 `encode` functions which manipulate `Bytes`
 
+## API
+
+
+You can use the `encode` and `decode` functions from the `IMultihash` interface provided you have an instance for your time.
+
+The current implementation support encoding and decoding `Bytes`.
+
+### Encoding 
+
+```idris
+||| Encode a digest along with the hash algorithm that was used
+decode : hash -> Either MultihashError (Multihash hash)
+```
+
+Implement this function in order to decode a `hash` type into a `Multihash`. `MultihashError` can be either `CodeNotFound` or `ParseErrro`.
+
+### Decoding
+
+```idris
+||| Attempts to decode raw bytes into a multihash
+encode : HashAlgorithm -> hash -> Multihash hash
+```
+
+Implement this function in order to encode a `hash` given a supported `HashAlgorithm`.
+
+The supported list of hashes are listed in the definition of `HashAlgorithm`:
+
+```idris
+data HashAlgorithm
+  = SHA1
+  | SHA256
+  | SHA512
+  | SHA3
+  | BLAKE2B
+  | BLAKE2S
+```
+
 ## Bytes dependency
 
 Since Multihash depends on bytes you might want to use it as well. Head to the [idris-bytes](https://github.com/ziman/idris-bytes) library in order to get more info. To summarize:
@@ -41,3 +81,7 @@ Since Multihash depends on bytes you might want to use it as well. Head to the [
 - Install it
 - Add `import Data.Bytes` (and maybe `import Data.ByteArray`) at the top of your file
 - run idris with `-p bytes` (typically `idris -p idris-multihash -p bytes`)
+
+
+In the future it would be possible to avoid this dependency by exposing a `String` based API by default and the `Bytes` 
+API as an additional import