doc: correct spelling of pointcloud

* fixed wiki text

Author: hrnr

map_merge_3d/doc/wiki.txt

@@ -19,7 +19,7 @@ In the multi-robot exploration scenario your robots probably run multiple ROS ma
 
 {{attachment:architecture.svg||width="755px"}}
 
-Recommended topics names for robot maps are `/robot1/map`, `/robot2/map` etc. However the names are configurable. All robots are expected to publish map under `<robot_namespace>/map`, where topic name (`map`) is configurable, but must be the same for all robots. For each robot `<robot_namespace>` is of cause different, but it does not need to follow any pattern. Further, you can exclude some topics using `robot_namespace` parameter, to avoid merging unrelated pointclouds.
+Recommended topics names for robot maps are `/robot1/map`, `/robot2/map` etc. However the names are configurable. All robots are expected to publish map under `<robot_namespace>/map`, where topic name (`map`) is configurable, but must be the same for all robots. For each robot `<robot_namespace>` is of cause different, but it does not need to follow any pattern. Further, you can exclude some topics using `robot_namespace` parameter, to avoid merging unrelated point clouds.
 
 == Estimation ==
 
@@ -187,7 +187,7 @@ prov_tf {
 
 == Tools ==
 
-Alongside ROS node {{{map_merge_3d}}} provides command-line tools to work with pointcloud maps saved in `pcd` files. Both tools accept any of the [[#REGISTRATION PARAMETERS]].
+Alongside ROS node {{{map_merge_3d}}} provides command-line tools to work with point cloud maps saved in `pcd` files. Both tools accept any of the [[#REGISTRATION PARAMETERS]].
 
 The tools use PCL command-line parsing module. PCL command-line parsing has some limits (PCL users won't be surprised): it supports only `--param value` format, `--param=value` is not accepted. Unknown options are ignored. Options may be arbitrarily mixed with filenames. There are no short versions for parameters.
 
@@ -217,7 +217,7 @@ Visualises pair-wise transform estimation between 2 maps. Uses PCL visualiser fo
 rosrun map_merge_3d registration_visualisation [--param value] map1.pcd map2.pcd
 }}}
 
-After one step of the estimation a visualisation window appears. You can freely navigate the pointcloud, save a screenshot or camera parameters (press `h` to see all shortcuts). After the window is closed, estimation continues with the next phase and the next visualisation window appears. Details about estimation progress are printed to `stdout`.
+After one step of the estimation a visualisation window appears. You can freely navigate the point cloud, save a screenshot or camera parameters (press `h` to see all shortcuts). After the window is closed, estimation continues with the next phase and the next visualisation window appears. Details about estimation progress are printed to `stdout`.
 
 == Acknowledgements ==