Added nuget publishing notes

publishing_to_nuget.md

@@ -0,0 +1,17 @@
+### 1. Pack:
+```
+dotnet pack Sieve.csproj -c Release -o . /p:PackageVersion=1.2.0
+```
+Don't forget to change version since nuget packages are immutable.
+
+### 2. Manually add nuspec:
+For some reason `dotnet pack` chooses to ignore my Sieve.nuspec.
+So unpack the Sieve.1.2.0.nupkg, and replace the nuspec in there with the local one.
+Don't forget that if you add new dependencies, you'll need to declare them in the nuspec.
+
+### 3. Publish:
+```
+nuget push Sieve.1.2.0.nupkg API_KEY -Source https://api.nuget.org/v3/index.json
+```
+Replace API_KEY with one you get from nuget's website.
+Also don't forget to replace corresponding version.