Programming exercise #12 Count, how many certain items exists in array of objects.

count.ts

// So, you have input data like this

let objArr = [
    { id: 1, name: 'Kamil' },
    { id: 2, name: 'Janusz' },
    { id: 3, name: 'Mariusz' },
    { id: 4, name: 'Alina' },
    { id: 5, name: 'Olo' } ];

// Please count, how many names in your array contains letter 'm'. 
// I suggest you, to use RXJS.