Remove dead README links (#676)

Author: jimmyjames

lib/src/main/java/com/auth0/jwt/algorithms/Algorithm.java

@@ -132,7 +132,6 @@ public static Algorithm RSA512(RSAKey key) throws IllegalArgumentException {
      *
      * @param secret the secret bytes to use in the verify or signing instance.
      *               Ensure the length of the secret is at least 256 bit long
-     *               See <a href="https://github.com/auth0/java-jwt#hmac-key-length-and-security">HMAC Key Length and Security in README</a>
      * @return a valid HMAC256 Algorithm.
      * @throws IllegalArgumentException if the provided Secret is null.
      */
@@ -145,7 +144,6 @@ public static Algorithm HMAC256(String secret) throws IllegalArgumentException {
      *
      * @param secret the secret bytes to use in the verify or signing instance.
      *               Ensure the length of the secret is at least 256 bit long
-     *               See <a href="https://github.com/auth0/java-jwt#hmac-key-length-and-security">HMAC Key Length and Security in README</a>
      * @return a valid HMAC256 Algorithm.
      * @throws IllegalArgumentException if the provided Secret is null.
      */
@@ -158,7 +156,6 @@ public static Algorithm HMAC256(byte[] secret) throws IllegalArgumentException {
      *
      * @param secret the secret bytes to use in the verify or signing instance.
      *               Ensure the length of the secret is at least 384 bit long
-     *               See <a href="https://github.com/auth0/java-jwt#hmac-key-length-and-security">HMAC Key Length and Security in README</a>
      * @return a valid HMAC384 Algorithm.
      * @throws IllegalArgumentException if the provided Secret is null.
      */
@@ -171,7 +168,6 @@ public static Algorithm HMAC384(String secret) throws IllegalArgumentException {
      *
      * @param secret the secret bytes to use in the verify or signing instance.
      *               Ensure the length of the secret is at least 384 bit long
-     *               See <a href="https://github.com/auth0/java-jwt#hmac-key-length-and-security">HMAC Key Length and Security in README</a>
      * @return a valid HMAC384 Algorithm.
      * @throws IllegalArgumentException if the provided Secret is null.
      */
@@ -184,7 +180,6 @@ public static Algorithm HMAC384(byte[] secret) throws IllegalArgumentException {
      *
      * @param secret the secret bytes to use in the verify or signing instance.
      *               Ensure the length of the secret is at least 512 bit long
-     *               See <a href="https://github.com/auth0/java-jwt#hmac-key-length-and-security">HMAC Key Length and Security in README</a>
      * @return a valid HMAC512 Algorithm.
      * @throws IllegalArgumentException if the provided Secret is null.
      */
@@ -197,7 +192,6 @@ public static Algorithm HMAC512(String secret) throws IllegalArgumentException {
      *
      * @param secret the secret bytes to use in the verify or signing instance.
      *               Ensure the length of the secret is at least 512 bit long
-     *               See <a href="https://github.com/auth0/java-jwt#hmac-key-length-and-security">HMAC Key Length and Security in README</a>
      * @return a valid HMAC512 Algorithm.
      * @throws IllegalArgumentException if the provided Secret is null.
      */