Improve documentation of project.el commands

* lisp/progmodes/project.el (project-find-regexp): Require 'grep'
to be able to call 'grep-read-files'.
(project-search, project-query-replace-regexp): Doc fixes.

* doc/emacs/maintaining.texi (Projects): New section.
* doc/emacs/emacs.texi (Top): Add "Projects" to the detailed menu.

1 files changed, 7 insertions, 4 deletions

diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index ccd8cc049d4..f4678681858 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -437,6 +437,7 @@ triggers completion when entering a pattern, including it
 requires quoting, e.g. `\\[quoted-insert]<space>'."
   (interactive (list (project--read-regexp)))
   (require 'xref)
+  (require 'grep)
   (let* ((pr (project-current t))
          (files
           (if (not current-prefix-arg)
@@ -606,7 +607,8 @@ PREDICATE, HIST, and DEFAULT have the same meaning as in
 (defun project-search (regexp)
   "Search for REGEXP in all the files of the project.
 Stops when a match is found.
-To continue searching for next match, use command \\[fileloop-continue]."
+To continue searching for the next match, use the
+command \\[fileloop-continue]."
   (interactive "sSearch (regexp): ")
   (fileloop-initialize-search
    regexp (project-files (project-current t)) 'default)
@@ -614,9 +616,10 @@ To continue searching for next match, use command \\[fileloop-continue]."
 
 ;;;###autoload
 (defun project-query-replace-regexp (from to)
-  "Search for REGEXP in all the files of the project.
-Stops when a match is found.
-To continue searching for next match, use command \\[fileloop-continue]."
+  "Query-replace REGEXP in all the files of the project.
+Stops when a match is found and prompts for whether to replace it.
+If you exit the query-replace, you can later continue the query-replace
+loop using the command \\[fileloop-continue]."
   (interactive
    (pcase-let ((`(,from ,to)
                 (query-replace-read-args "Query replace (regexp)" t t)))