updated to v3.0.0 updating target framework from .NET Core 3.1 to .NET 7

Author: h0lg

.vscode/launch.json

@@ -9,7 +9,7 @@
             "type": "coreclr",
             "request": "launch",
             "preLaunchTask": "build",
-            "program": "${workspaceFolder}/bin/Debug/netcoreapp3.1/SubTubular.dll",
+            "program": "${workspaceFolder}/bin/Debug/net7.0/SubTubular.dll",
             "args": [],
             "cwd": "${workspaceFolder}",
             //https://github.com/OmniSharp/omnisharp-vscode/blob/master/debugger-launchjson.md#console-terminal-window

SubTubular.csproj

@@ -2,11 +2,11 @@
 <Project Sdk="Microsoft.NET.Sdk" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net7.0</TargetFramework>
     <ApplicationIcon>SubTubular.ico</ApplicationIcon>
     <AssemblyTitle>SubTubular - full-text search in YouTube video subtitles and metadata</AssemblyTitle>
     <Product>SubTubular</Product>
-    <VersionPrefix>2.3.0</VersionPrefix>
+    <VersionPrefix>3.0.0</VersionPrefix>
     <Description>A command-line for full-text-searching YouTube video subtitles and metadata.</Description>
     <Authors>Holger Schmidt</Authors>
     <Copyright>Copyright © Holger Schmidt 2020</Copyright>