Add `cargo-readme`-generated README

`cargo readme --no-license > README.markdown`
Commit time

Created tique/README.markdown

@@ -1,0 +1,33
+# tique
+Utilities to drive a tantivy search index
+## Overview
+### `conditional_collector`
+Collectors with built-in support for changing the ordering and
+cursor-based pagination (or rather: support for conditionally
+skipping documents that match the query).
+use tique::conditional_collector::{Ascending, TopCollector};
+let min_rank_collector =
+ TopCollector::<f64, Ascending, _>::new(10, true).top_fast_field(f64_field);
+Check the module docs for more details.
+### Unstable
+This crate also contains unpolished functionality that is made availble
+through the `unstable` feature flag:
+* `tique::query_parser`: A very simple query parser that only knows
+ about term and phrase queries (and their negation). Mostly an excuse
+ to play with `nom`
+* `tique_derive::FilterAndAggregation`: Takes a struct of (possibly
+ `Option`) primitives and generates a bunch of code to assist with
+ indexing, filtering and aggregating.