$ cat /usr/share/X11/xkb/symbols/xkb-capslock-vim
partial keypad_keys
xkb_symbols "capslock-vim" {
# replace Caps with AltGr
key <CAPS> { [ ISO_Level3_Shift ] };
# Add vim cursor keys to be accessed with AltGr
key <AC06> { [ h, H , Left, Left ] };
key <AC07> { [ j, J, Down, Down ] };
key <AC08> { [ k, K, Up, Up ] };
key <AC09> { [ l, L, Right, Right ] };
key <AD08> { [ i, I, Home, Home ] };
key <AC10> { [ semicolon, colon, End, End ] };
key <AD07> { [ u, U, BackSpace, BackSpace ] };
key <AB09> { [ period, greater, Delete, Delete ] };
key <AB06> { [ n, N, Next, Next ] };
key <AB07> { [ m, M, Prior, Prior ] };
#key <AB08> { [ comma, less, BackSpace, BackSpace ] };
#key <AB09> { [ period, greater, Delete, Delete ] };
#key <AC11> { [ apostrophe, quotedbl, End, End ] };
};