Merge pull request #82 from kc8apf/arch_docs docs: Fix poor grammar

diff --git a/docs/architecture/overview.rst b/docs/architecture/overview.rst
index fb58e60..ec66cfb 100644
--- a/docs/architecture/overview.rst
+++ b/docs/architecture/overview.rst

@@ -17,7 +17,7 @@
 as related to configuration. The halves are referred to simply as the top and
 bottom halves.
 
-Each halves is next divided vertically into one or more :term:`horizontal clock
+Each half is next divided vertically into one or more :term:`horizontal clock
 rows <horizontal clock row>`, numbered outward from the global clock buffer
 dividing line. Each horizontal clock row contains 12 clock lines that extend
 across the device perpendicular to the global clock spine.  Similar to the