By Max Hunder (Reuters) – Ukraine’s southern port of Mariupol has been under fire since early in Russia’s invasion of Ukraine and a siege has trapped tens of thousands of people there with dwindling supplies. Here is a timeline of main events there. Feb. 24 – Russia launches a full-scale invasion of Ukraine from three fronts and begins to advance towards Mariupol from parts of eastern Ukraine controlled by Russia-backed separatists, and from annexed Crimea in the south. Local authorities say 26 people are admitted to hospital after parts of the city are shelled. March 1 – Mayor Vadym Boichenko…