style(doc): shorten some first paragraph descriptions

src/directed/astar.rs

@@ -147,9 +147,11 @@ where
 }
 
 /// Compute all shortest paths using the [A* search
-/// algorithm](https://en.wikipedia.org/wiki/A*_search_algorithm). Whereas `astar`
-/// (non-deterministic-ally) returns a single shortest path, `astar_bag` returns all shortest paths
-/// (in a non-deterministic order).
+/// algorithm](https://en.wikipedia.org/wiki/A*_search_algorithm).
+
+/// Whereas `astar` (non-deterministic-ally) returns a single shortest
+/// path, `astar_bag` returns all shortest paths (in a
+/// non-deterministic order).
 ///
 /// The shortest paths starting from `start` up to a node for which `success` returns `true` are
 /// computed and returned in an iterator along with the cost (which, by definition, is the same for
@@ -273,9 +275,11 @@ where
 }
 
 /// Compute all shortest paths using the [A* search
-/// algorithm](https://en.wikipedia.org/wiki/A*_search_algorithm). Whereas `astar`
-/// (non-deterministic-ally) returns a single shortest path, `astar_bag` returns all shortest paths
-/// (in a non-deterministic order).
+/// algorithm](https://en.wikipedia.org/wiki/A*_search_algorithm).
+
+/// Whereas `astar` (non-deterministic-ally) returns a single shortest
+/// path, `astar_bag` returns all shortest paths (in a
+/// non-deterministic order).
 ///
 /// This is a utility function which collects the results of the `astar_bag` function into a
 /// vector. Most of the time, it is more appropriate to use `astar_bag` directly.

src/directed/dfs.rs

@@ -7,9 +7,10 @@ use std::iter::FusedIterator;
 
 /// Compute a path using the [depth-first search
 /// algorithm](https://en.wikipedia.org/wiki/Depth-first_search).
-/// The path starts from `start` up to a node for which `success` returns `true` is computed and
-/// returned along with its total cost, in a `Some`. If no path can be found, `None` is returned
-/// instead.
+///
+/// The path starts from `start` up to a node for which `success`
+/// returns `true` is computed and returned along with its total cost,
+/// in a `Some`. If no path can be found, `None` is returned instead.
 ///
 /// - `start` is the starting node.
 /// - `successors` returns a list of successors for a given node, which will be tried in order.

src/grid.rs

@@ -13,6 +13,8 @@ use std::iter::FusedIterator;
 use std::ops::Sub;
 
 #[derive(Clone)]
+/// A rectangular grid.
+///
 /// Representation of a rectangular grid in which vertices can be added
 /// or removed. Edges are automatically created between adjacent vertices.
 /// By default, only vertical and horizontal edges are created, unless