[flang] fix bad indentation in README

Original-commit: flang-compiler/f18@60a0123f46b74d3fad942bf359ebe5ba11da5cdd
Reviewed-on: https://github.com/flang-compiler/f18/pull/6
Tree-same-pre-rewrite: false
1 file changed
tree: 47678768e4861ce8b2bc43f06aeef69df1f61d3d
  1. flang/