docs: add new journal command documentation

Replace the attribute system documentation with new documentation for
the variable system, roll command, link command, and spark command.

src/components/journal-doc-data.ts

@@ -43,9 +43,19 @@ function parseEntry(raw: string): JournalDocEntry | null {
 
 import journalGmRaw from "../doc-entries/journal-gm.md";
 import journalPlayerRaw from "../doc-entries/journal-player.md";
-import journalStatRaw from "../doc-entries/journal-stat.md";
+import journalSetRaw from "../doc-entries/journal-set.md";
+import journalRollRaw from "../doc-entries/journal-roll.md";
+import journalSparkRaw from "../doc-entries/journal-spark.md";
+import journalLinkRaw from "../doc-entries/journal-link.md";
 
-const rawDocuments: string[] = [journalGmRaw, journalPlayerRaw, journalStatRaw];
+const rawDocuments: string[] = [
+  journalGmRaw,
+  journalPlayerRaw,
+  journalSetRaw,
+  journalRollRaw,
+  journalSparkRaw,
+  journalLinkRaw,
+];
 
 let _entries: JournalDocEntry[] | null = null;