Update index.html

grammar mistake
In visualization creation, make the icons the same width for consistency
Fixed typo in tooltip.
Merge pull request #1848 from lukasolson/consistent-icon-size

In visualization creation, make the icons the same width for consistency
Merge pull request #1854 from paulbakker/master

Fixed typo in tooltip.
replace local ruby-version file
update contributing docs with rbenv instructions
Change the case of the Data Table vis type to match the case of the other vis types.
simplified the installation instructions
Merge pull request #1865 from w33ble/ruby-docs

Update ruby instructions in CONTRIBUTING
Merge pull request #1866 from lukasolson/change-data-table-case

Data Table letter case doesn't match other vis types
[vislib/tileMap] skip checking the size of the container for now
[visualize] fail fast when the query doesn't contain any hits
[timefilter] ensure that the timefilter always has a default value
Merge pull request #1870 from spenceralger/default_times_timepicker

[timefilter] ensure that the timefilter always has a default value
[vislib/layout] ensure that the top level svg in a chart is block, not inline
Merge pull request #1871 from spenceralger/pie-scrolls

Fix the constant scroll bar on the pie
Merge pull request #1846 from ChrisJNL/patch-1

Fix a grammar mistake in advanced settings
preserve the query string in the searchSource, if it exists