link up man references (#213)

doc/man/man3/index.txt

@@ -8,3 +8,11 @@ notcurses_input(3)    notcurses_input.3.ronn
 notcurses_output(3)   notcurses_output.3.ronn
 notcurses_render(3)   notcurses_render.3.ronn
 notcurses_stop(3)     notcurses_stop.3.ronn
+
+poll(2)               http://man7.org/linux/man-pages/man2/poll.2.html
+getenv(3)             http://man7.org/linux/man-pages/man3/getenv.3.html
+termios(3)            http://man7.org/linux/man-pages/man3/termios.3.html
+ncurses(3NCURSES)     http://man7.org/linux/man-pages/man3/ncurses.3x.html
+terminfo(5)           http://man7.org/linux/man-pages/man5/terminfo.5.html
+signal(7)             http://man7.org/linux/man-pages/man7/signal.7.html
+unicode(7)            http://man7.org/linux/man-pages/man7/unicode.7.html

doc/man/man3/notcurses_input.3.ronn

@@ -5,6 +5,27 @@ notcurses_input(3) -- input via notcurses
 
 `#include <notcurses.h>`
 
+<pre>typedef struct ncinput {
+  char32_t id;     // Unicode codepoint
+  int y;           // Y cell coordinate of event, -1 for undefined
+  int x;           // X cell coordinate of event, -1 for undefined
+  bool alt;        // Was Alt held during the event?
+  bool shift;      // Was Shift held during the event?
+  bool ctrl;       // Was Ctrl held during the event?
+} ncinput;</pre>
+
+`bool nckey_mouse_p(char32_t r);`
+
+`char32_t notcurses_getc(struct notcurses* n, const struct timespec* ts, sigset_t* sigmask, ncinput* ni);`
+
+`char32_t notcurses_getc_nblock(struct notcurses* n, ncinput* ni);`
+
+`char32_t notcurses_getc_blocking(struct notcurses* n, ncinput* ni);`
+
+`int notcurses_mouse_enable(struct notcurses* n);`
+
+`int notcurses_mouse_disable(struct notcurses* n);`
+
 ## DESCRIPTION
 
 
@@ -16,4 +37,4 @@ Nick Black <nickblack@linux.com>
 
 ## SEE ALSO
 
-notcurses(3)
+notcurses(3), poll(2), unicode(7)