By Nidal al-Mughrabi and Dan Williams GAZA/JERUSALEM (Reuters) -An Egyptian-mediated truce between Israel and Hamas began on Friday and U.S. President Joe Biden pledged to salve the devastated Gaza Strip with humanitarian aid after the worst fighting in years. Palestinians, many of whom had spent 11 days huddled in fear of Israeli shelling, poured into Gaza’s streets. Mosque loud-speakers feted “the victory of the resistance achieved over the Occupation (Israel) during the ‘Sword of Jerusalem’ battle”. In the countdown to the 2 a.m. (2300 GMT Thursday) cease-fire, Palestinian rocket salvoes co…