treewide: add meta.mainProgram to some libraries

where a single bin is provided and someone might actually want to run it

pkgs/development/libraries/sqlite/tools.nix

@@ -2,7 +2,7 @@
 
 let
   archiveVersion = import ./archive-version.nix lib;
-  mkTool = { pname, makeTarget, description, homepage }: stdenv.mkDerivation rec {
+  mkTool = { pname, makeTarget, description, homepage, mainProgram }: stdenv.mkDerivation rec {
     inherit pname;
     version = "3.38.2";
 
@@ -20,7 +20,7 @@ let
     installPhase = "install -Dt $out/bin ${makeTarget}";
 
     meta = with lib; {
-      inherit description homepage;
+      inherit description homepage mainProgram;
       downloadPage = "http://sqlite.org/download.html";
       license = licenses.publicDomain;
       maintainers = with maintainers; [ johnazoidberg ];
@@ -34,11 +34,13 @@ in
     makeTarget = "sqldiff";
     description = "A tool that displays the differences between SQLite databases";
     homepage = "https://www.sqlite.org/sqldiff.html";
+    mainProgram = "sqldiff";
   };
   sqlite-analyzer = mkTool {
     pname = "sqlite-analyzer";
     makeTarget = "sqlite3_analyzer";
     description = "A tool that shows statistics about SQLite databases";
     homepage = "https://www.sqlite.org/sqlanalyze.html";
+    mainProgram = "sqlite3_analyzer";
   };
 }