Add: Networking and HTTP sections

Also, use new version of
unpackaged/org-export-html-with-useful-ids-mode, which makes better
anchors and links.

Author: alphapapa

README.org

@@ -34,6 +34,7 @@ You can read this Org file directly on the [[https://github.com/alphapapa/emacs-
     -  [[#general][General]]
     -  [[#highlighting--font-locking][Highlighting / font-locking]]
     -  [[#multiprocessing-generators-threads][Multiprocessing (generators, threads)]]
+    -  [[#networking][Networking]]
     -  [[#packaging][Packaging]]
     -  [[#pattern-matching][Pattern matching]]
     -  [[#profiling--optimization][Profiling / Optimization]]
@@ -819,6 +820,38 @@ Chris Wellons explains the new generators and threads that Emacs 26 provides.  H
 
 **** [[https://www.gnu.org/software/emacs/draft/manual/html_node/elisp/Threads.html][GNU Emacs Lisp Reference Manual: Threads]]                    :threads:
 
+** Networking                                                   :networking:
+
+*** HTTP                                                             :HTTP:
+
+**** Libraries                                                 :libraries:
+
+For simple use cases, and some more complex ones, the built-in [[*=url=][url]] library should be sufficient.  Libraries that use =curl=, such as [[*%5B%5Bhttps://github.com/tkf/emacs-request%5D%5BRequest.el%20--%20Easy%20HTTP%20requests%5D%5D][request]], can provide better performance and more flexibility.  However, in this author's experience, both of those tools, while mostly reliable, tend to have some obscure bugs that can occasionally be problematic.
+
+***** [[https://github.com/skeeto/elfeed/blob/master/elfeed-curl.el][elfeed-curl]]                                                  :curl:
+
+Not a standalone package, but part of [[https://github.com/skeeto/elfeed/blob/master/elfeed-curl.el][Elfeed]].  A solid, well-designed library, but purpose-built for Elfeed.  Could easily be adapted to other packages or factored out as a separate package.
+
+***** [[https://github.com/cinsk/emacs-curl][emacs-curl: CURL wrapper]]                                     :curl:
+
+A very simple =curl= wrapper, last updated in 2012.  Not published on MELPA.
+
+****** COMMENT Maybe remove this
+
+It's unlikely to be useful at this point.  Maybe list it in an appendix or something, for completeness's sake.
+
+***** [[https://github.com/leathekd/grapnel][grapnel: HTTP request lib built on curl with flexible callback dispatch]] :curl:
+
+A flexible, featureful =curl= wrapper, last updated in 2015.
+
+***** [[https://github.com/tkf/emacs-request][Request.el -- Easy HTTP requests]]                      :curl:url_el:
+
+=request= is the most commonly used third-party HTTP library.  It has both =curl= and =url.el= backends.
+
+***** =url=                                               :url_el:built_in:
+
+=url= is included with Emacs and used by a variety of packages.
+
 ** Packaging                                                     :packaging:
 :PROPERTIES:
 :TOC:      ignore-children