Revise and fix typos in reference documentation

[jxblum]

I have noticed grammar mistakes, or just changes in wording to make things more clear/concise along with broken links as I read through SD Redis's docs.

[jxblum]

I created the topic/issue branch with my changes to date; more editing to do yet.

[mp911de]

Full report of links that we should revisit (redirects, broken links, error 500s):

  Module           Status           URL
  ---------------  ---------------  ------------------------------------------------------------------------------------------------------------------------------------------------------
  Redis            302              https://spring.io/docs
  Redis            302              https://www.google.com/search?q=nosoql+acronym
  Redis            301              https://github.com/spring-projects/spring-data-keyvalue-examples
  Redis            404              https://spring.io/blog/2011/04/27/getting-started-redis-spring-cloud-foundry/
  Redis            301              https://pivotal.io/
  Redis            302              https://spring.io/spring-data
  Redis            302              https://github.com/spring-projects/spring-data-redis/issues/new
  Redis            302              https://github.com/spring-projects/spring-data-examples/tree/master/bom
  Redis            404              https://spring.io/tools/sts
  Redis            301              https://github.com/xetorthio/jedis
  Redis            301              https://redis.io/topics/sentinel
  Redis            301              https://redis.io/commands
  Redis            301              https://blogs.oracle.com/java-platform-group/entry/incoming_filter_serialization_data_a
  Redis            301              https://openjdk.java.net/jeps/290
  Redis            301              https://www.owasp.org/index.php/Deserialization_of_untrusted_data
  Redis            301              https://redis.io/topics/streams-intro
  Redis            301              https://redis.io/topics/transactions
  Redis            301              https://redis.io/topics/pipelining
  Redis            301              https://redis.io/commands/eval
  Redis            301              https://redis.io/commands/evalsha
  Redis            302              https://download.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/package-summary.html
  Redis            302              https://download.oracle.com/javase/8/docs/api/java/util/Collection.html
  Redis            301              https://redis.io/topics/cluster-spec
  Redis            301              https://redis.io/topics/cluster-tutorial
  Redis            500              /cdn-cgi/l/email-protection
  Redis            301              https://redis.io/topics/indexes
  Redis            301              https://redis.io/topics/notifications