Merge pull request #25 from mansimas/patch_docs

docs/Aggregation/Avg.md

docs/Aggregation/Cardinality.md

docs/Aggregation/Children.md

docs/Aggregation/DateRange.md

docs/Aggregation/ExtendedStats.md

docs/Aggregation/Filter.md

docs/Aggregation/Filters.md

docs/Aggregation/GeoBounds.md

docs/Aggregation/GeoHashGrid.md

docs/Aggregation/Global.md

docs/Aggregation/Histogram.md

docs/Aggregation/Ipv4Range.md

docs/Aggregation/Missing.md

docs/Aggregation/Nested.md

docs/Aggregation/PercentileRanks.md

docs/Aggregation/Percentiles.md

docs/Aggregation/Range.md

docs/Aggregation/ReverseNested.md

docs/Aggregation/Stats.md

docs/Aggregation/Sum.md