Minor grammar fixes

Minor grammar fixes at lines 9 and 93.

13.md

@@ -6,7 +6,7 @@ Proof of Work
 
 `draft` `optional` `author:jb55` `author:cameri`
 
-This NIP defines a way to generate and interpret Proof of Work for nostr notes. Proof of Work (PoW) is a way to add a proof of computational work to a note. This is a bearer proof which all relays and clients can universally validate with a small amount of code. This proof can be used as a means of spam deterrence.
+This NIP defines a way to generate and interpret Proof of Work for nostr notes. Proof of Work (PoW) is a way to add a proof of computational work to a note. This is a bearer proof that all relays and clients can universally validate with a small amount of code. This proof can be used as a means of spam deterrence.
 
 `difficulty` is defined to be the number of leading zero bits in the `NIP-01` id. For example, an id of `000000000e9d97a1ab09fc381030b346cdd7a142ad57e6df0b46dc9bef6c7e2d` has a difficulty of `36` with `36` leading 0 bits.
 
@@ -90,4 +90,4 @@ $ echo '["REQ", "subid", {"ids": ["000000000"]}]'  | websocat wss://some-relay.c
 Delegated Proof of Work
 -----------------------
 
-Since the `NIP-01` note id does not commit to any signature, PoW can be outsourced to PoW providers, perhaps for a fee. This provides a way for clients to get their messages out to PoW restricted relays without having to do any work themselves, which is useful for energy constrained devices like on mobile
+Since the `NIP-01` note id does not commit to any signature, PoW can be outsourced to PoW providers, perhaps for a fee. This provides a way for clients to get their messages out to PoW-restricted relays without having to do any work themselves, which is useful for energy constrained devices like on mobile