Fix typos and markdowns

Found via these commands:

    codespell -L crate,ser,panting,beauti,hart,ue,atleast,childs,ond,pris,hel,mot
    markdownlint *.md doc/src/*.md --disable MD013 MD025 MD033 MD001 MD024 MD036 MD041 MD003

src/termdict/fst_termdict/mod.rs

@@ -7,7 +7,7 @@
 //! For instance, in a dictionary containing the sorted terms "abba", "bjork", "blur" and "donovan",
 //! the `TermOrdinal` are respectively `0`, `1`, `2`, and `3`.
 //!
-//! For `u64`-terms, tantivy explicitely uses a `BigEndian` representation to ensure that the
+//! For `u64`-terms, tantivy explicitly uses a `BigEndian` representation to ensure that the
 //! lexicographical order matches the natural order of integers.
 //!
 //! `i64`-terms are transformed to `u64` using a continuous mapping `val ⟶ val - i64::MIN`

src/termdict/fst_termdict/streamer.rs

@@ -87,7 +87,7 @@ where A: Automaton
 {
     /// Advance position the stream on the next item.
     /// Before the first call to `.advance()`, the stream
-    /// is an unitialized state.
+    /// is an uninitialized state.
     pub fn advance(&mut self) -> bool {
         if let Some((term, term_ord)) = self.stream.next() {
             self.current_key.clear();

src/termdict/mod.rs

@@ -7,7 +7,7 @@
 //! For instance, in a dictionary containing the sorted terms "abba", "bjork", "blur" and "donovan",
 //! the [TermOrdinal] are respectively `0`, `1`, `2`, and `3`.
 //!
-//! For `u64`-terms, tantivy explicitely uses a `BigEndian` representation to ensure that the
+//! For `u64`-terms, tantivy explicitly uses a `BigEndian` representation to ensure that the
 //! lexicographical order matches the natural order of integers.
 //!
 //! `i64`-terms are transformed to `u64` using a continuous mapping `val ⟶ val - i64::MIN`

src/termdict/sstable_termdict/sstable/sstable_index.rs

@@ -35,7 +35,7 @@ pub struct BlockAddr {
 struct BlockMeta {
     /// Any byte string that is lexicographically greater or equal to
     /// the last key in the block,
-    /// and yet stricly smaller than the first key in the next block.
+    /// and yet strictly smaller than the first key in the next block.
     pub last_key_or_greater: Vec<u8>,
     pub block_addr: BlockAddr,
 }

src/termdict/sstable_termdict/streamer.rs

@@ -101,7 +101,7 @@ where
 {
     /// Advance position the stream on the next item.
     /// Before the first call to `.advance()`, the stream
-    /// is an unitialized state.
+    /// is an uninitialized state.
     pub fn advance(&mut self) -> bool {
         while self.delta_reader.advance().unwrap() {
             self.term_ord = Some(