.NET DllExport 1.8.1. Public release

Fixed Pre-Proc ILMerge "path is not of a legal form." netstandard2.1 & 2.0

ILAsm 9.4 (+49d4bece) & update netcore assets after final changes

3F's IL Assembler 9.4; support PDB (MSF + Portable(BSJB))

+Remove x86+x64 .dlls [Ref] dependencies when merging

Fixed ILMerge support for rebasing feature due to missed _PathToResolvedTargetingPack

+Code of Conduct & new YAML issue templates

Pack of trivial UI changes:

Fixed #245. The method or operation is not implemented

Fix netfx-based assemblers: Failed to define a document writer

Use split '$(IsNetCoreBased)'!='true' only if there is a difference

+PDB support (MSF + Portable) for 3F's assembler (9.4+)

Fixed PreProc $(TargetName).dll only for ILMerge + ILRepack

Allow [Ref] without merging

updated DllExport.bat 1.8 for assets;