migrations: Add 6.sql: Begin outline index

shared/migrations/6.sql

@@ -0,0 +1,2 @@
+CREATE TABLE outline(id INTEGER PRIMARY KEY, fileid INTEGER REFERENCES file (id) ON DELETE CASCADE, text varchar(1024), page integer);
+CREATE INDEX outline_fileid ON outline (fileid);

shared/migrations/migrations.qrc

@@ -5,5 +5,6 @@
         <file>3.sql</file>
         <file>4.sql</file>
         <file>5.sql</file>
+        <file>6.sql</file>
     </qresource>
 </RCC>