Return the position to insert a given function doc in a notebook.

def get_insert_idx(pos_dict, name):
    "Return the position to insert a given function doc in a notebook."
    keys,i = list(pos_dict.keys()),0
    while i < len(keys) and str.lower(keys[i]) < str.lower(name): i+=1
    if i == len(keys): return -1
    else:              return pos_dict[keys[i]]