less: Add hotkeys f and b to scroll screen up/down

Base/usr/share/man/man1/less.md

@@ -35,7 +35,8 @@ does not exist, and no command use `N`.
 | `q` | Exit less. |
 | `j` or `DOWNARROW` or `ENTER` | Go to the next line. |
 | `k` or `UPARROW` | Go to the previous line. |
-| `SPACE` | Go to the next page. |
+| `f` or `SPACE` | Go to the next page. |
+| `b` | Go to the previous page. |
 
 ## Prompts
 

Userland/Utilities/less.cpp

@@ -622,9 +622,9 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
                     else
                         pager.bottom();
                 }
-            } else if (sequence == " " || sequence == "\e[6~") {
+            } else if (sequence == " " || sequence == "f" || sequence == "\e[6~") {
                 pager.down_page();
-            } else if (sequence == "\e[5~" && !emulate_more) {
+            } else if ((sequence == "\e[5~" || sequence == "b") && !emulate_more) {
                 pager.up_page();
             } else if (sequence == "d") {
                 pager.down_half_page();