git-worktree.txt: consistently use term "working tree"

As originally composed, git-worktree.txt employed a mix of "worktree"
and "working tree" which was inconsistent and potentially confusing to
readers. bc483285b7 (Documentation/git-worktree: consistently use term
"linked working tree", 2015-07-20) undertook the task of employing the
term "working tree" consistently throughout the document and avoiding
"worktree" altogether for descriptive text. Since that time, some
instances of "worktree" have crept back in. Continue the work of
bc483285b7 by transforming these to "working tree", as well.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-worktree.txt

@@ -70,20 +70,20 @@ branches from there if `<branch>` is ambiguous but exists on the
 linkgit:git-config[1].
 +
 If `<commit-ish>` is omitted and neither `-b` nor `-B` nor `--detach` used,
-then, as a convenience, the new worktree is associated with a branch
+then, as a convenience, the new working tree is associated with a branch
 (call it `<branch>`) named after `$(basename <path>)`.  If `<branch>`
 doesn't exist, a new branch based on `HEAD` is automatically created as
 if `-b <branch>` was given.  If `<branch>` does exist, it will be
-checked out in the new worktree, if it's not checked out anywhere
-else, otherwise the command will refuse to create the worktree (unless
+checked out in the new working tree, if it's not checked out anywhere
+else, otherwise the command will refuse to create the working tree (unless
 `--force` is used).
 
 list::
 
-List details of each worktree.  The main worktree is listed first, followed by
-each of the linked worktrees.  The output details include if the worktree is
-bare, the revision currently checked out, and the branch currently checked out
-(or "detached HEAD" if none).
+List details of each working tree.  The main working tree is listed first,
+followed by each of the linked working trees.  The output details include
+if the working tree is bare, the revision currently checked out, and the
+branch currently checked out (or "detached HEAD" if none).
 
 lock::
 
@@ -202,7 +202,7 @@ This can also be set up as the default behaviour by using the
 	absolute.
 +
 If the last path components in the working tree's path is unique among
-working trees, it can be used to identify worktrees. For example if
+working trees, it can be used to identify working trees. For example if
 you only have two working trees, at `/abc/def/ghi` and `/abc/def/ggg`,
 then `ghi` or `def/ghi` is enough to point to the former working tree.
 
@@ -221,7 +221,7 @@ shared.
 
 Refs that are per working tree can still be accessed from another
 working tree via two special paths, `main-worktree` and `worktrees`. The
-former gives access to per-worktree refs of the main working tree,
+former gives access to per-working tree refs of the main working tree,
 while the latter to all linked working trees.
 
 For example, `main-worktree/HEAD` or `main-worktree/refs/bisect/good`
@@ -335,8 +335,8 @@ Porcelain Format
 The porcelain format has a line per attribute.  Attributes are listed with a
 label and value separated by a single space.  Boolean attributes (like `bare`
 and `detached`) are listed as a label only, and are only present if and only
-if the value is true.  The first attribute of a worktree is always `worktree`,
-an empty line indicates the end of the record.  For example:
+if the value is true.  The first attribute of a working tree is always
+`worktree`, an empty line indicates the end of the record.  For example:
 
 ------------
 $ git worktree list --porcelain