documentation: fix typos

Diff best viewed with --color-diff.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/technical/commit-graph.txt

@@ -136,7 +136,7 @@ Design Details
 
 - Commit grafts and replace objects can change the shape of the commit
   history. The latter can also be enabled/disabled on the fly using
-  `--no-replace-objects`. This leads to difficultly storing both possible
+  `--no-replace-objects`. This leads to difficulty storing both possible
   interpretations of a commit id, especially when computing generation
   numbers. The commit-graph will not be read or written when
   replace-objects or grafts are present.

Documentation/technical/parallel-checkout.txt

@@ -148,7 +148,7 @@ information, the main process handles the results in two steps:
 
 - First, it updates the in-memory index with the `lstat()` information
   sent by the workers. (This must be done first as this information
-  might me required in the following step.)
+  might be required in the following step.)
 
 - Then it writes the items which collided on disk (i.e. items marked
   with `PC_ITEM_COLLIDED`). More on this below.
@@ -232,7 +232,7 @@ conversion and re-encoding, are eligible for parallel checkout.
 Ineligible entries are checked out by the classic sequential codepath
 *before* spawning workers.
 
-Note: submodules's files are also eligible for parallel checkout (as
+Note: submodules' files are also eligible for parallel checkout (as
 long as they don't fall into any of the excluding categories mentioned
 above). But since each submodule is checked out in its own child
 process, we don't mix the superproject's and the submodules' files in