Update c++-abbreviations.vim
Update c++-abbreviations.vim

Use `[&]` and `const auto &`
- in lambdas for sort and accumulate

Signed-off-by: Karel Ha <70f8965fdfb04f1fc0e708a55d9e822c449f57d3@gmail.com>

mathemage/CompetitiveProgramming,mathemage/CompetitiveProgramming,mathemage/CompetitiveProgramming,mathemage/CompetitiveProgramming,mathemage/CompetitiveProgramming,mathemage/CompetitiveProgramming