feat: additionally sort postings by their creation date, if they are not (in ascending manner)

[pursvir]

I think this program should also sort postings by their creation date, in case if they are shuffled, like in the example below:

2026-07-05 Taco bell | 10,000 cups of water
    Expenses:Groceries  5000 USD
    Assets:JPMorganBank

2026-07-03 Walmart | Two bottles of milk
    Expenses:Diary  10 USD
    Assets:Cash

2026-07-09 My company | Salary
    Assets:JPMorganBank  1 USD
    Income:Salary

So that the result would be this:

2026-07-03 Walmart | Two bottles of milk
    Expenses:Diary  10 USD
    Assets:Cash

2026-07-05 Taco bell | 10,000 cups of water
    Expenses:Groceries  5000 USD
    Assets:JPMorganBank

2026-07-09 My company | Salary
    Assets:JPMorganBank  1 USD
    Income:Salary