fix typos (#257)

index.html

@@ -833,7 +833,7 @@ <h2>cnf</h2>
  <a data-cite="VC-DATA-MODEL-2.0#dfn-verify">verification</a> process.
  </p>
  <p>
- Use of a proof-of-posssion key provided by the Holder to the Issuer
+ Use of a proof-of-possession key provided by the Holder to the Issuer
  to establish a cryptographic binding to the Holder in the Verifiable Credential
  that is verifiable by the Verifier in the Verifiable Presentation is RECOMMENDED.
  </p>
@@ -986,7 +986,7 @@ <h3>Verification Material</h3>
 A <a>verification method</a> MUST NOT contain multiple verification material
 properties for the same material. For example, expressing key material in a
 <a>verification method</a> using both `publicKeyJwk` and
-another representtion is prohibited.
+another representation is prohibited.
  </p>
 
  <p>
@@ -2238,7 +2238,7 @@ <h2>Controllers</h2>
  "x": "ANRjH_zxcKBxsjRPUtzRbp7FSVLKJXQ9APX9MP1j7k4"
  }
  }, {
- "id": "#subject-authenticaton",
+ "id": "#subject-authentication",
  "type": "JsonWebKey",
  "controller": "did:web:vendor.example",
  "publicKeyJwk": {
@@ -2270,7 +2270,7 @@ <h2>Controllers</h2>
  "x": "qLZkSTbstvMWPTivmiQglEFWG2Ff7gNDVoVisdZTr1I"
  }
  }],
- "authentication": ["#subject-authenticaton"],
+ "authentication": ["#subject-authentication"],
  "assertionMethod": ["#credential-issuance"]
 }
  </pre>