Fix some typos, grammars and Increase readability documentation

[AhyoungRyu]

What is this PR for?

It would be better if Zeppelin provides looking good documentation.

What type of PR is it?

Improvement

Todos

• - Fix typos, grammars and Increase readability writingzeppelininterpreter.md
• - Also spark.md
• - tutorial.md
• - cassandra.md
• - elasticsearch.md
• - flink.md
• - hive.md
• - lens.md
• - markdown.md
• - rest-interpreter.md

Is there a relevant Jira issue?

No : )

How should this be tested?

These documentations are in here.

Screenshots (if appropriate)

Questions:

• Does the licenses files need update? No
• Is there breaking changes for older versions? No
• Does this needs documentation? No

[Leemoonsoo]

./bin/zeppelin-daemon.sh start is the correct one.

[AhyoungRyu]

You are right. I fixed it.

[HeartSaVioR]

nit: space between l and `

[AhyoungRyu]

@HeartSaVioR Thank you for your kind reviewing! I applied the comments that you mentioned.
And I'll commit the rest of TODO.

[AhyoungRyu]

I checked out several docs pages(in the above TODO list), since there are some grammar error or typos or bad alignment. Actually I want to checkout another pages too in this PR, but I saw the other PR which fix same docs pages. So after this PR merged, I will open another PR for them.

So far, below pages also have to be checked.

• - install.md (a table in this docs is little bit not pretty(?))
• - table.md
• - angular.md
• - notebookashomepage.md
• - rest-notebook.md
• - howtocontribute.md
• - howtocontributewebsite.md
• - Remove the duplicated section between interpreter.md and writingzeppelininterpreter.md
• - Divide display.md into text.md & html.md
• - Divide storage.md into gitstorage.md & s3storage.md

[AhyoungRyu]

So, ready to review : )

[Leemoonsoo]

LGTM. Thanks @AhyoungRyu improving docs!

[felixcheung]

we might want to keep lowered case for null, boolean tuple and udt since the actual types are lowered case? http://docs.datastax.com/en/cql/3.1/cql/cql_reference/tupleType.html

[AhyoungRyu]

@felixcheung
I really appreciate to your prudent review : )
All your comments are make sense, so I applied them.

[corneadoug]

Once you have build....
-> Once you have built your interpreter, you can place it under the interpreter directory with all its dependencies.

[corneadoug]

While reviewing this PR, I found out that the docs/development/writingzeppelininterpreter.md might not be accurate.

For example, in https://github.com/apache/incubator-zeppelin/blob/master/docs/development/writingzeppelininterpreter.md#configure-your-interpreter

The interpreter should be added to conf/zeppelin-site.xml.template only (since conf/zeppelin-site.xml is user configuration)

And the part about default configuration should not be as a 'Note' but as a step to do.

In the end, it should look like this:

Configure your interpreter

To configure your interpreter you need to follow these steps:

1. Add your interpreter class name to the zeppelin.interpreters property in conf/zeppelin-site.xml.template

   Property value is comma separated [INTERPRETER_CLASS_NAME].

   For example:

   <property>
   <name>zeppelin.interpreters</name>
   <value>org.apache.zeppelin.spark.SparkInterpreter,org.apache.zeppelin.spark.PySparkInterpreter,org.apache.zeppelin.spark.SparkSqlInterpreter,org.apache.zeppelin.spark.DepInterpreter,org.apache.zeppelin.markdown.Markdown,org.apache.zeppelin.shell.ShellInterpreter,org.apache.zeppelin.hive.HiveInterpreter,com.me.MyNewInterpreter</value>
   </property>
   

2. Add your interpreter to the default configuration which is used when there is no zeppelin-site.xml.

3. Start zeppelin by running ./bin/zeppelin-deamon start

4. In the interpreter page, click the +Create button and configure your interpreter properties.
   Now you are done and ready to use your interpreter.

[felixcheung]

@corneadoug looks good, I'd only add in 2, instead of a specific line number, could we refer to it as:
"
Add your interpreter to the ZEPPELIN_INTERPRETERS() list in zeppelin-zengine/src/main/java/org/apache/zeppelin/conf/ZeppelinConfiguration.java
"

[felixcheung]

... although, shouldn't point 1 & 2 be part of https://github.com/apache/incubator-zeppelin/blob/master/docs/development/writingzeppelininterpreter.md#make-your-own-interpreter instead they should be code changes to include in the PR for the new interpreter?

[corneadoug]

@felixcheung I thing its fine in this category since the step before is adding the interpreter under the right folder

[felixcheung]

@corneadoug but point 2 is code change that someone creating a new interpreter should do, right?

[corneadoug]

Yes, but its more things to do when adding the interpreter to Zeppelin

[AhyoungRyu]

@corneadoug@felixcheung I applied the comments : )

[corneadoug]

Honestly, there is too much changes in that PR to properly review all the grammar and sentences.
But I think that overall the changes are good, and people can always fix the docs later :) LGTM

[Leemoonsoo]

LGTM i'm merging