docs: Prefer the form "cannot" to "can not"

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #242
Approved by: cgwalters

docs/manual/related-projects.md

@@ -63,7 +63,7 @@ awareness of BTRFS in dpkg/rpm itself) will be required.
 The OSTree author believes that having total freedom at the block
 storage layer is better for general purpose operating systems. For
 example, with OSTree, one is free to use BTRFS in any way you like -
-you can use a subvolume for `/home`, or you can not.
+you can use a subvolume for `/home`, or you cannot.
 
 Furthermore, in its most basic incarnation, the rpm/dpkg + BTRFS
 doesn't solve the race conditions that happen when unpacking packages

docs/manual/repository-management.md

@@ -179,7 +179,7 @@ you should update the summary file:
 ostree --repo=repo-prod summary -u
 ```
 
-(Remember, the `summary` command can not be run concurrently, so this
+(Remember, the `summary` command cannot be run concurrently, so this
  should be triggered serially by other jobs).
 
 There is some more information on the design of the summary file in