fix typo and rearrange words in `src/appModel.ts`

[hamirmahal]

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[x] Other: <!-- Please describe: -->
This change fixes a typo.

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information