If writeable is OK, so is overwriteable

Both should probably appear in the en-GB_to_en-US dictionary instead of
the standard dictionary.

codespell_lib/data/dictionary.txt

@@ -42354,7 +42354,6 @@ overwridden->overridden, overwritten,
 overwride->overwrite, override,
 overwrides->overwrites, overrides,
 overwriding->overwriting, overriding,
-overwriteable->overwritable
 overwrited->overwritten, overwrote,
 overwriten->overwritten
 overwritin->overwriting

codespell_lib/data/dictionary_en-GB_to_en-US.txt

@@ -323,6 +323,7 @@ organiser->organizer
 organisers->organizers
 organises->organizes
 organising->organizing
+overwriteable->overwritable
 parallelisation->parallelization
 parallelise->parallelize
 parallelised->parallelized
@@ -522,3 +523,4 @@ visualised->visualized
 visualiser->visualizer
 visualises->visualizes
 visualising->visualizing
+writeable->writable