docs/config.txt: reorder hideRefs config

The descriptions for receive.hideRefs and
uploadpack.hideRefs are largely the same, and then
transfer.hideRefs refers to both of them. Instead, let's
make transfer.hideRefs the "master" source, and refer to it
from the other sites (with appropriate program-specific
annotations).

This avoids duplication, and will make it easier to document
changes to the config option without having to copy and
paste the description in two places.

While we're at it, this fixes some bogus subject/verb
agreement in the original description.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -2242,13 +2242,10 @@ receive.denyNonFastForwards::
 	set when initializing a shared repository.
 
 receive.hideRefs::
-	String(s) `receive-pack` uses to decide which refs to omit
-	from its initial advertisement.  Use more than one
-	definitions to specify multiple prefix strings. A ref that
-	are under the hierarchies listed on the value of this
-	variable is excluded, and is hidden when responding to `git
-	push`, and an attempt to update or delete a hidden ref by
-	`git push` is rejected.
+	This variable is the same as `transfer.hideRefs`, but applies
+	only to `receive-pack` (and so affects pushes, but not fetches).
+	An attempt to update or delete a hidden ref by `git push` is
+	rejected.
 
 receive.updateServerInfo::
 	If set to true, git-receive-pack will run git-update-server-info
@@ -2536,9 +2533,13 @@ transfer.fsckObjects::
 	Defaults to false.
 
 transfer.hideRefs::
-	This variable can be used to set both `receive.hideRefs`
-	and `uploadpack.hideRefs` at the same time to the same
-	values.  See entries for these other variables.
+	String(s) `receive-pack` and `upload-pack` use to decide which
+	refs to omit from their initial advertisements.  Use more than
+	one definition to specify multiple prefix strings. A ref that is
+	under the hierarchies listed in the value of this variable is
+	excluded, and is hidden when responding to `git push` or `git
+	fetch`.  See `receive.hideRefs` and `uploadpack.hideRefs` for
+	program-specific versions of this config.
 
 transfer.unpackLimit::
 	When `fetch.unpackLimit` or `receive.unpackLimit` are
@@ -2553,13 +2554,10 @@ uploadarchive.allowUnreachable::
 	`false`.
 
 uploadpack.hideRefs::
-	String(s) `upload-pack` uses to decide which refs to omit
-	from its initial advertisement.  Use more than one
-	definitions to specify multiple prefix strings. A ref that
-	are under the hierarchies listed on the value of this
-	variable is excluded, and is hidden from `git ls-remote`,
-	`git fetch`, etc.  An attempt to fetch a hidden ref by `git
-	fetch` will fail.  See also `uploadpack.allowTipSHA1InWant`.
+	This variable is the same as `transfer.hideRefs`, but applies
+	only to `upload-pack` (and so affects only fetches, not pushes).
+	An attempt to fetch a hidden ref by `git fetch` will fail.  See
+	also `uploadpack.allowTipSHA1InWant`.
 
 uploadpack.allowTipSHA1InWant::
 	When `uploadpack.hideRefs` is in effect, allow `upload-pack`