Add .desktop file for XDG compatible DEs (#501)

Install with `make install-desktop`
It now appears in application menus, search, etc. in XDG compatible
desktop environments (like GNOME, KDE, ...).

Makefile

@@ -2,6 +2,7 @@ VERSION = $(shell grep -m1 VERSION $(SRC) | cut -f 2 -d'"')
 
 PREFIX ?= /usr/local
 MANPREFIX ?= $(PREFIX)/share/man
+DESKTOPPREFIX ?= $(PREFIX)/share/applications
 STRIP ?= strip
 PKG_CONFIG ?= pkg-config
 INSTALL ?= install
@@ -81,6 +82,7 @@ DISTFILES = src nnn.1 Makefile README.md LICENSE
 SRC = src/nnn.c
 HEADERS = src/nnn.h
 BIN = nnn
+DESKTOPFILE = misc/desktop/nnn.desktop
 
 all: $(BIN)
 
@@ -92,6 +94,13 @@ debug: $(BIN)
 norl: $(BIN)
 noloc: $(BIN)
 
+install-desktop: $(DESKTOPFILE)
+	$(INSTALL) -m 0755 -d $(DESTDIR)$(DESKTOPPREFIX)
+	$(INSTALL) -m 0644 $(DESKTOPFILE) $(DESTDIR)$(DESKTOPPREFIX)
+
+uninstall-desktop:
+	$(RM) $(DESTDIR)$(DESKTOPPREFIX)/$(DESKTOPFILE)
+
 install: all
 	$(INSTALL) -m 0755 -d $(DESTDIR)$(PREFIX)/bin
 	$(INSTALL) -m 0755 $(BIN) $(DESTDIR)$(PREFIX)/bin
@@ -135,4 +144,4 @@ clean:
 
 skip: ;
 
-.PHONY: all install uninstall strip static dist sign upload-local clean
+.PHONY: all install uninstall strip static dist sign upload-local clean install-desktop uninstall-desktop

misc/desktop/nnn.desktop

@@ -0,0 +1,10 @@
+[Desktop Entry]
+Type=Application
+Name=nnn
+Comment=Terminal file manager
+Exec=nnn
+Terminal=true
+Icon=utilities-terminal
+MimeType=inode/directory
+Categories=System;FileTools;FileManager;ConsoleOnly
+Keywords=File;Manager;Management;Explorer;Launcher