Make snapshot file type automatic

[timea-solid]

Needs change to line:

SolidHelloWorlds/src/adminPage/adminSnapshots.js

Line 27 in c5f5cdd

const timestampx = x.substring(x.lastIndexOf('-')+1, x.indexOf('.ttl'))

and

SolidHelloWorlds/src/adminPage/adminSnapshots.js

Line 42 in c5f5cdd

const timestamp = sortedSnapshotFileNames[i].substring(sortedSnapshotFileNames[i].lastIndexOf('-') + 1, sortedSnapshotFileNames[i].indexOf('.ttl'))

and

SolidHelloWorlds/src/adminPage/snapshots/snapshot.js

Line 51 in c5f5cdd

const timestampx = x.substring(x.lastIndexOf('-')+1, x.indexOf('.ttl'))

and