Clarify locking behavior

Signed-off-by: Marek Kubica <[email protected]>

Author: Leonidas-from-XIV

doc/tutorials/dune-package-management/locking.md

@@ -9,10 +9,12 @@ use new versions of their dependencies. However some projects might want to
 keep a fixed set of dependencies that is only updated manually. This can be
 done in multiple ways.
 
-## Create a lock directory
+## Create a lock directory manually
 
-Dune locks dependencies by creating lock directories. The default lock 
-directory is called `dune.lock`. To create a lock, run
+Dune resolves dependencies by creating an internal lock directory
+automatically. However, if an manually created lock directory exists in the
+source, Dune will use that one instead. The default name of said lock directory
+is `dune.lock`, and it can be created manually:
 
 ```
 $ dune pkg lock
@@ -24,7 +26,7 @@ Solution for dune.lock:
 
 Whenever Dune encounters a `dune.lock` folder, it will use the set of
 dependencies defined in the lock. The lock will not be updated until a user
-relocks by running `dune pkg lock` again.
+creates a new lock by running `dune pkg lock` again.
 
 On the next build, Dune will read the solution from the `dune.lock` directory,
 download and build the dependencies and then continue on building the project