Remove more references to "master"

Bug: chromium:1101491
Bug: b/161896447

Switch to more inclusive language, like "main", or remove where
simply unnecessary.

Change-Id: I36ef6ec631eb991f54f42b98887333f07c0984c2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/306060
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
diff --git a/tools/doxygen/Doxyfile b/tools/doxygen/Doxyfile
index 66fad82..61b12e5 100644
--- a/tools/doxygen/Doxyfile
+++ b/tools/doxygen/Doxyfile
@@ -1352,7 +1352,7 @@
 HHC_LOCATION           =
 
 # The GENERATE_CHI flag controls if a separate .chi index file is generated
-# (YES) or that it should be included in the master .chm file (NO).
+# (YES) or that it should be included in the main .chm file (NO).
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTMLHELP is set to YES.