Remove misleading information about deprecated/disabled time based index pattern.

[gavenkoa]

https://www.elastic.co/guide/en/kibana/current/index-patterns.html#settings-create-pattern says:

To use an event time in an index name, enclose the static text in the pattern and specify the date format using the tokens described in the following table.

For example, [logstash-]YYYY.MM.DD matches all indices whose names have a timestamp of the form YYYY.MM.DD appended to the prefix logstash-, such as logstash-2015.01.31 and logstash-2015-02-01.

and has dedicated "Table 2. Date Format Tokens".

According to #4342 time based patterns are disabled. I even created https://stackoverflow.com/questions/44629994/is-kibana-date-format-index-pattern-still-supported/ because of that misleading docs.

Those two paragraphs and table should be removed. Not sure why during #5275 that page wasn't updated.

[cjcenizal]

Thanks! The docs have been updated.