Output the distribution of English words by their first letter (ignoring case).

Program.cs

// Steps to reproduce assuming you have dotnet installed (using version 6).
// mkdir english-word-distribution && cd english-word-distribution
// dotnet new console
// curl https://raw.githubusercontent.com/dwyl/english-words/master/words.txt --output words.txt
// dotnet run
var letterCount = new Dictionary<char, int>();
foreach (var word in File.ReadLines("words.txt"))
{
    var letter = word.ToLower()[0];
    if (!letterCount.ContainsKey(letter))
    {
        letterCount[letter] = 0;
    }
    letterCount[letter]++;
}
foreach (var letter in letterCount.OrderBy(lc => lc.Key))
{
    Console.WriteLine($"{letter.Key},{letter.Value}");
}