rest-api: Fix capitalisation of 'Just'

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/rest-api.md b/rest-api.md
index 1d61eb5..10b01e9 100644
--- a/rest-api.md
+++ b/rest-api.md
@@ -151,7 +151,7 @@
         -d '{"data": <value>}' \
         https://bmc/org/openbmc/control/flash/bios/attr/flasher_path
 
-When using '-d' Just remember that json requires quoting.
+When using '-d' just remember that json requires quoting.
 
 ## HTTP POST operations
 POST operations are for calling methods, but also for creating new resources