root: added DOTNET's nupkg implementations

Since DOTNET's nupkg is quite simple to create and to upstream,
it's best we support it from the start. Besides, the Chocolatey
is one of the nupkg implementations so no worries.

This patch adds DOTNET's nupkg implementations in root
repository.

Co-authored-by: Shuralyov, Jean <jean.shuralyov@proton.me>
Co-authored-by: Galyna, Cory <cory.galyna@gmail.com>
Co-authored-by: (Holloway) Chew, Kean Ho <me@hollowaykeanho.com>
Signed-off-by: (Holloway) Chew, Kean Ho <me@hollowaykeanho.com>

.gitignore

@@ -140,6 +140,11 @@ gh-pages/
 #####################
 *.log
 
+#####################
+# GNU
+#####################
+.gsf-save*
+
 #####################
 # MacOS specifics
 #####################