feat: Improve Brigadier Documentation (#507)

Co-authored-by: powercas_gamer <cas@mizule.dev>
Co-authored-by: Ollie <69084614+olijeffers0n@users.noreply.github.com>
Co-authored-by: Matouš Kučera <mk@kcra.me>
Co-authored-by: Timon Seidel <timong.seidel@gmail.com>

_redirects

@@ -7,4 +7,6 @@
 /paper/per-world-configuration /paper/configuration
 /paper/configuration /paper/reference/configuration
 /paper/reference/vanilla-command-permissions /paper/reference/permissions
-/paper/dev/commands /paper/dev/command-api/commands
+/paper/dev/commands /paper/dev/command-api/basics/introduction
+/paper/dev/command-api/commands /paper/dev/command-api/basics/introduction
+/paper/dev/command-api/arguments /paper/dev/command-api/basics/arguments-and-literals

config/sidebar.paper.ts

@@ -131,7 +131,45 @@ const paper: SidebarsConfig = {
               type: "category",
               label: "Brigadier Command API",
               collapsed: true,
-              items: ["dev/api/command-api/commands", "dev/api/command-api/arguments"],
+              items: [
+                {
+                  type: "category",
+                  label: "Basics",
+                  collapsed: true,
+                  items: [
+                    "dev/api/command-api/basics/introduction",
+                    "dev/api/command-api/basics/command-tree",
+                    "dev/api/command-api/basics/arguments-and-literals",
+                    "dev/api/command-api/basics/executors",
+                    "dev/api/command-api/basics/registration",
+                    "dev/api/command-api/basics/requirements",
+                  ],
+                },
+                {
+                  type: "category",
+                  label: "Arguments",
+                  collapsed: true,
+                  items: [
+                    "dev/api/command-api/arguments/minecraft",
+                    "dev/api/command-api/arguments/location",
+                    "dev/api/command-api/arguments/entity-player",
+                    "dev/api/command-api/arguments/registry",
+                    "dev/api/command-api/arguments/paper",
+                    "dev/api/command-api/arguments/enums",
+                    "dev/api/command-api/arguments/predicate",
+                    "dev/api/command-api/arguments/adventure",
+                  ],
+                },
+                {
+                  type: "category",
+                  label: "Misc",
+                  collapsed: true,
+                  items: [
+                    "dev/api/command-api/misc/comparison-bukkit-brigadier",
+                    "dev/api/command-api/misc/basic-command",
+                  ],
+                },
+              ],
             },
             {
               type: "category",