Add C#/.NET git ignore

[francis04j]

Task: Add C# option

Expected output

`

Build Folders

bin/ obj/

User-specific files

*.rsuser *.suo *.user *.userosscache *.sln.docstates

Logs

*.log

Environment variables

.env

Visual Studio Code settings

.vscode/

Rider settings

.idea/

Windows image file caches

Thumbs.db ehthumbs.db

Folder config file

Desktop.ini

Recycle Bin used on file shares

$RECYCLE.BIN/

Project files generated by popular JetBrains IDEs

*.sln.iml

IIS Express settings

.vs/ .vscode/

DotNet specific files

project.lock.json project.fragment.lock.json artifacts/

ASP.NET Scaffolding

ScaffoldingReadMe.txt

Azure Web Apps log directory

azuredeploy.json

`