Fix spelling mistakes in documentation
While reading  some of the docs I noticed a few errors, so I ran
misspellings (https://pypi.python.org/pypi/misspellings) on markdown files
@@ -689,7 +689,7 @@ process is returned by the `docker attach` command to its caller too:
--memory-swap="" Total memory (memory + swap), `-1` to disable swap
-c, --cpu-shares CPU Shares (relative weight)
--cpuset-mems="" MEMs in which to allow execution, e.g. `0-3`, `0,1`
- --cpuset-cpus="" CPUs in which to allow exection, e.g. `0-3`, `0,1`
+ --cpuset-cpus="" CPUs in which to allow execution, e.g. `0-3`, `0,1`
--cgroup-parent="" Optional parent cgroup for the container
Builds Docker images from a Dockerfile and a "context". A build's context is
@@ -759,7 +759,7 @@ client is killed for any reason.
> **Note:**
> Currently only the "run" phase of the build can be canceled until pull
-> cancelation is implemented).
+> cancellation is implemented).
### Return code
