Merge #876: Fix typos in comments

cc0b834  Fix typos in comments (mlombardi)

Pull request description:

  Fixes three typos found in the codebase:
  
    - `constuct` → `construct` (src/descriptor/mod.rs:159) 
    - `satisified` → `satisfied` (src/miniscript/context.rs:786)


ACKs for top commit:
  apoelstra:
    ACK cc0b834; successfully ran local tests


Tree-SHA512: 47df803ad080a8151f7b975838b75911a1526864a5f942c39f354d354aa12f0cfd0fe130c201c4255edc61388d0e6d4392fd25f79771909abfd6a7c0b6b98398

Author: apoelstra

src/descriptor/mod.rs

@@ -156,7 +156,7 @@ impl<Pk: MiniscriptKey> Descriptor<Pk> {
 
     /// Create a new pk descriptor
     pub fn new_pk(pk: Pk) -> Self {
-        // roundabout way to constuct `c:pk_k(pk)`
+        // roundabout way to construct `c:pk_k(pk)`
         let ms: Miniscript<Pk, BareCtx> = Miniscript::from_ast(Terminal::Check(Arc::new(
             Miniscript::from_ast(Terminal::PkK(pk)).expect("Type check cannot fail"),
         )))

src/miniscript/context.rs

@@ -783,7 +783,7 @@ impl ScriptContext for BareCtx {
 
 /// "No Checks Ecdsa" Context
 ///
-/// Used by the "satisified constraints" iterator, which is intended to read
+/// Used by the "satisfied constraints" iterator, which is intended to read
 /// scripts off of the blockchain without doing any sanity checks on them.
 /// This context should *NOT* be used unless you know what you are doing.
 #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]