general: Add back Makefile.

Makefile

+PREFIX ?= /usr
+MANDIR ?= $(PREFIX)/share/man
+
+all:
+	@echo Run \'make install\' to install Neofetch.
+
+install:
+	@mkdir -p $(DESTDIR)$(PREFIX)/bin
+	@mkdir -p $(DESTDIR)$(MANDIR)/man1
+	@cp -p neofetch $(DESTDIR)$(PREFIX)/bin/neofetch
+	@cp -p neofetch.1 $(DESTDIR)$(MANDIR)/man1
+	@chmod 755 $(DESTDIR)$(PREFIX)/bin/neofetch
+
+uninstall:
+	@rm -rf $(DESTDIR)$(PREFIX)/bin/neofetch
+	@rm -rf $(DESTDIR)$(MANDIR)/man1/neofetch.1*