added autocmd hooks for screensaver commands

added a landing page for the help command

nix/render_rc.nix

@@ -53,6 +53,9 @@ lib.concatLines [
       (lib.concatLines (lib.mapAttrsToList (name: value: "export ${name}=\"${value}\"") cfg.environmentVars))
       (lib.concatLines (lib.mapAttrsToList (name: value: "alias ${name}=\"${value}\"") cfg.aliases))
       (lib.concatLines [
+        "shopt line.viewport_height=${toString cfg.settings.viewportHeight}"
+        "shopt line.scroll_offset=${toString cfg.settings.scrollOffset}"
+
         "shopt core.dotglob=${boolToString cfg.settings.dotGlob}"
         "shopt core.autocd=${boolToString cfg.settings.autocd}"
         "shopt core.hist_ignore_dupes=${boolToString cfg.settings.historyIgnoresDupes}"

nix/shed_opts.nix

@@ -155,6 +155,18 @@
     description = "Additional completion scripts to source when shed starts (e.g. for custom tools or functions)";
   };
 
+  viewportHeight = {
+    type = lib.types.either lib.types.int lib.types.str;
+    default = "50%";
+    description = "Maximum viewport height for the line editor buffer";
+  };
+
+  scrollOffset = {
+    type = lib.types.int;
+    default = "1";
+    description = "The minimum number of lines to keep visible above and below the cursor when scrolling (i.e. the 'scrolloff' option in vim)";
+  };
+
   environmentVars = lib.mkOption {
     type = lib.types.attrsOf lib.types.str;
     default = {};