Console application for scanning files

FileScanner

using System;
using System.IO;
using System.Linq;

namespace FileScanner
{
    public class Program
    {
        private const string _locationOfRepoToScan = @"C:\Development\IdentiyServer\IdentityServer4\src\IdentityServer4";
        private const string _localDirectoryReplace = @"C:\Development\IdentiyServer\IdentityServer4\";
        private const string _gitHubRepoLocationReaplace = "https://github.com/LindaLawton/IdentityServer4/blob/GDPR/";
        private const int _gitLineNumberOffset = 1;
        private static string  _mydocpath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
        private static string _outputFile = _mydocpath + @"\IdentityServerGDPRScann.txt";

        private const string _SearchFor = "_logger.";
        private const string _InFilesOfType = ".cs";

        public static void Main(string[] args)
        {
            if (File.Exists(_outputFile))
            {
                File.Delete(_outputFile);
            }

            if (Directory.Exists(_locationOfRepoToScan))
            {
                ProcessDirectory(_locationOfRepoToScan);
            }
        }

        // Process all files in the directory passed in, recurse on any directories 
        // that are found, and process the files they contain.
        public static void ProcessDirectory(string targetDirectory)
        {
            // Process the list of files found in the directory.
            var fileEntries = Directory.GetFiles(targetDirectory).Where(a => Path.GetExtension(a) == _InFilesOfType).ToList();
            foreach (var fileName in fileEntries)
                ProcessFile(fileName);

            // Recurse into subdirectories of this directory.
            var subdirectoryEntries = Directory.GetDirectories(targetDirectory);
            foreach (var subdirectory in subdirectoryEntries)
                ProcessDirectory(subdirectory);
        }

        public static void ProcessFile(string path)
        {
            using (var outputFile = new StreamWriter(_outputFile, true))
            {
                var lines = File.ReadLines(path)
                    .Select((line, lineNumber) => new { LineNumber = lineNumber, Line = line })
                    .Where(line => line.Line.Contains(_SearchFor))
                    .ToList();

                if (lines.Count <= 0) return;
                outputFile.Output("\r\n");
                outputFile.Output($"[{Path.GetFileName(path)}]({BuildGitHubLink(path)})");
                foreach (var line in lines)
                {
                    outputFile.Output($"{line.LineNumber + _gitLineNumberOffset}. `{line.Line.Trim()}` [{Path.GetFileName(path)}]({BuildGitHubLink(path)}#L{line.LineNumber + _gitLineNumberOffset})");
                }
            }
        }

        public static string BuildGitHubLink(string path)
        {
            return path.Replace(_localDirectoryReplace, _gitHubRepoLocationReaplace).Replace("\\", "/");
            
        }
    }

    public static class StreamWriterExtensions
    {
        public static void Output(this StreamWriter stream, string line)
        {
            Console.WriteLine(line);  // I like to watch while debuging.
            stream.WriteLine(line);
        }
    }
}