dotnet --info output:
.NET-Befehlszeilentools (2.1.103)
Product Information:
Version: 2.1.103
Commit SHA-1 hash: 60218cecb5
Runtime Environment:
OS Name: Windows
OS Version: 10.0.15063
OS Platform: Windows
RID: win10-x64
Base Path: D:\Program Files\dotnet\sdk\2.1.103\
Microsoft .NET Core Shared Framework Host
Version : 2.0.6
Build : 74b1c703813c8910df5b96f304b0f2b78cdf194d
VS Code version: 1.22.2
C# Extension version: 1.14.0
Open Unity project in VS Code.
Try to type "On..."

Show autocomplete for Unity events like "OnTriggerEnter(Collider col)" or "Update()".
Doesn't show autocomplete.
Marking this as a feature request as it is for custom completion support for Unity.
There are many snippet packs which approximate this functionality when you search for "unity snippets" in extensions manager.
Most popular one: https://github.com/YclepticStudios/vscode-unity-snippets.
Fork without xml docs: https://github.com/lionize/vscode-unity-snippets
Just ran into the same issue. Checking to see if there's something I've missed. Snippets definitely work great. Is this the only/recommended way?
Most helpful comment
There are many snippet packs which approximate this functionality when you search for "unity snippets" in extensions manager.
Most popular one: https://github.com/YclepticStudios/vscode-unity-snippets.
Fork without xml docs: https://github.com/lionize/vscode-unity-snippets