open: improve grammar (#3397)

pages/osx/open.md

@@ -10,7 +10,7 @@
 
 `open -a {{Application}}`
 
-- Run a graphical macOS app based on the bundle identifier (refer to `osascript` for an easy way get this):
+- Run a graphical macOS app based on the bundle identifier (refer to `osascript` for an easy way to get this):
 
 `open -b {{com.domain.application}}`
 
@@ -18,7 +18,7 @@
 
 `open .`
 
-- Reveal a file in finder:
+- Reveal a file in Finder:
 
 `open -R {{path/to/file}}`