title: Shouldn't the login be a Query in GraphQL?
body: <p>In the <a href="https://www.howtographql.com/graphql-js/6-authentication/" rel="noreferrer">tutorial</a> on GraphQL authentication, the <code>login</code> is a <strong>Mutation</strong>:</p>
  
  <pre><code>type Mutation {
    post(url: String!, description: String!): Link!
    signup(email: String!, password: String!, name: String!): AuthPayload
    login(email: String!, password: String!): AuthPayload
  }
  </code></pre>
  
  <p>Shouldn't the login be a <strong><em>Query</em></strong> since:</p>
  
  <ol>
  <li>The operation has no side-effects on the server.</li>
  <li>The goal is to <em>query</em> a token.</li>
  </ol>
  
  <p>Am I missing something here ?</p>