Add IRC to makefile, disallow purple on x86_gcc2

Makefile

@@ -3,16 +3,27 @@
 app:
 	$(MAKE) -f application/Makefile
 
-protocols:
-	$(MAKE) -f protocols/Makefile
 libs:
 	$(MAKE) -f libs/Makefile
 
+irc:
+	$(MAKE) -f protocols/irc/Makefile
+
+xmpp:
+	$(MAKE) -f protocols/xmpp/Makefile
+
+purple:
+ifneq ($(shell uname -m), x86_gcc2)
+	$(MAKE) -f protocols/purple/Makefile
+endif
+
+protocols: irc xmpp purple
+
+all: libs protocols app
+
 clean:
 	$(MAKE) -f application/Makefile clean
 
-all: libs protocols app
-
 .PHONY: libs protocols
 
 default: all

README.md

@@ -1,10 +1,21 @@
 # Cardie
 ![GSoC 2021](https://img.shields.io/badge/GSoC-2021-green.svg)
 
-A multi-protocol chat program based on [Caya](https://github.com/Augustolo/Caya).
+Cardie is a multi-protocol chat program based on [Caya](https://github.com/Augustolo/Caya).
+
+It can use native protocol add-ons and protocols supported by libpurple, the
+library used by [Pidgin](https://pidgin.im/).
+
+Protocols natively supported are:
+- IRC
+- XMPP
+
+Protocols generally supported through libpurple include GroupWise, Zephyr, and
+[others through plugins](https://pidgin.im/plugins/?type=Protocol).
 
 ![Screenshot](data/screenshots/update-3.png)
 
+
 ## Building
 You can make Cardie and its protocols with:
 
@@ -16,11 +27,8 @@ Or one-by-one:
 
 Cardie itself requires the `expat_devel` package, the XMPP protocol requires
 `gloox_devel`, and the libpurple add-on requires `libpurple_devel` and
-`glib2_devel`.
+`glib2_devel`― though it's worth noting that libpurple doesn't work on x86_gcc2.
 
-The (provisional) IRC protocol has to be built specifically:
-
-`$ make -f protocols/irc/Makefile`
 
 ## License
 Cardie itself is under the MIT license, but licenses vary for the included