Sargent Shriver, the founding director of the Peace Corps, died yesterday at the age of 95. A true public servant, he was never elected to any political office — he was, however, George McGovern's vice-presidential running mate in the 1972 presidential election. In addition to his work with the Peace Corps, Mr. Shriver became a chief architect of President Johnson's War on Poverty, served as ambassador to France, and headed the Special Olympics which was founded by his wife Eunice Kennedy Shriver.