lavd/x11grab: apply misc consistency fixes to options definition

In particular, do not upcase first word, do not use final dot, use a verb
to specify what the option does, sort entries by name, apply random
vertical align.

libavdevice/x11grab.c

@@ -581,13 +581,16 @@ x11grab_read_close(AVFormatContext *s1)
 #define OFFSET(x) offsetof(struct x11grab, x)
 #define DEC AV_OPT_FLAG_DECODING_PARAM
 static const AVOption options[] = {
-    { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = "vga"}, 0, 0, DEC },
-    { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC },
-    { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { 1 }, 0, 1, DEC },
-    { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
-      OFFSET(follow_mouse), AV_OPT_TYPE_INT, { 0 }, -1, INT_MAX, DEC, "follow_mouse" },
-    { "centered", "Keep the mouse pointer at the center of grabbing region when following.", 0, AV_OPT_TYPE_CONST, { -1 }, INT_MIN, INT_MAX, DEC, "follow_mouse" },
-    { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { 0 }, 0, 1, DEC },
+    { "draw_mouse", "draw the mouse pointer", OFFSET(draw_mouse), AV_OPT_TYPE_INT, {1}, 0, 1, DEC },
+
+    { "follow_mouse", "move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region",
+      OFFSET(follow_mouse), AV_OPT_TYPE_INT, {0}, -1, INT_MAX, DEC, "follow_mouse" },
+    { "centered",     "keep the mouse pointer at the center of grabbing region when following",
+      0, AV_OPT_TYPE_CONST, {-1}, INT_MIN, INT_MAX, DEC, "follow_mouse" },
+
+    { "framerate",  "set video frame rate",      OFFSET(framerate),   AV_OPT_TYPE_STRING,     {.str = "ntsc"}, 0, 0, DEC },
+    { "show_region", "show the grabbing region", OFFSET(show_region), AV_OPT_TYPE_INT,        {0}, 0, 1, DEC },
+    { "video_size",  "set video frame size",     OFFSET(width),       AV_OPT_TYPE_IMAGE_SIZE, {.str = "vga"}, 0, 0, DEC },
     { NULL },
 };