v0.0.82 Added description of MTT synchronization

What's Changed

• smmtt updates per TG calls on 4/30, 5/14 by @rsahita in #48

-Moved theory of operation of memory isolation (non-normative) to intro chapter 1
-Updated figure showing logical enforcement of MTT (hart and IO side accesses)
-Updated intro to extensions chapter 2
-Added clarification on SDID usage as local id, PMP usage
-Added description of MTT synchronization (MFENCE.SPA, MINVAL.SPA)
-Fixed glossary errors