codespell: config, workflow and some typos fixed

.codespellrc

@@ -0,0 +1,3 @@
+[codespell]
+skip = .git,*.pdf,*.svg
+ignore-words-list = crate,dne

.github/workflows/codespell.yml

@@ -0,0 +1,22 @@
+---
+name: Codespell
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+permissions:
+  contents: read
+
+jobs:
+  codespell:
+    name: Check for spelling errors
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Codespell
+        uses: codespell-project/actions-codespell@v2

src/cmd/split.rs

@@ -24,7 +24,7 @@ Usage:
 split options:
     -s, --size <arg>       The number of records to write into each chunk.
                            [default: 500]
-    -j, --jobs <arg>       The number of spliting jobs to run in parallel.
+    -j, --jobs <arg>       The number of splitting jobs to run in parallel.
                            This only works when the given CSV data has
                            an index already created. Note that a file handle
                            is opened for each job.

src/cmd/stats.rs

@@ -423,7 +423,7 @@ impl Commute for FieldType {
             (TNull, any) | (any, TNull) => any,
             // There's no way to get around an unknown.
             (TUnknown, _) | (_, TUnknown) => TUnknown,
-            // Integers can degrate to floats.
+            // Integers can degrade to floats.
             (TFloat, TInteger) | (TInteger, TFloat) => TFloat,
             // Numbers can degrade to Unicode strings.
             (TUnicode, TFloat) | (TFloat, TUnicode) => TUnicode,

src/util.rs

@@ -146,7 +146,7 @@ pub fn range(start: Idx, end: Idx, len: Idx, index: Idx)
     }
 }
 
-/// Create a directory recursively, avoiding the race conditons fixed by
+/// Create a directory recursively, avoiding the race conditions fixed by
 /// https://github.com/rust-lang/rust/pull/39799.
 fn create_dir_all_threadsafe(path: &Path) -> io::Result<()> {
     // Try 20 times. This shouldn't theoretically need to be any larger