Add codespell support (config, workflow to detect/not fix) and make it fix some typos

.codespellrc

@@ -0,0 +1,6 @@
+[codespell]
+# Ref: https://github.com/codespell-project/codespell#using-a-config-file
+skip = .git*,.codespellrc
+check-hidden = true
+# ignore-regex = 
+# ignore-words-list =

.github/workflows/codespell.yml

@@ -0,0 +1,25 @@
+# Codespell configuration is within .codespellrc
+---
+name: Codespell
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  codespell:
+    name: Check for spelling errors
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Annotate locations with typos
+        uses: codespell-project/codespell-problem-matcher@v1
+      - name: Codespell
+        uses: codespell-project/actions-codespell@v2

README.md

@@ -18,7 +18,7 @@ sub\-XXXX\_ses\-Y\_task\-{rest, other\_task\_name}\_run\-ZZ\_desc\-confounds\_ti
 (or specifically, for example:
 sub\-BB06601\_ses\-1\_task\-rest\_run\-02\_desc\-confounds\_timeseries.tsv)
 
-While this *confound* file contains a large number of metrics, we have specific interest in sumarising the following metrics:
+While this *confound* file contains a large number of metrics, we have specific interest in summarising the following metrics:
 
 * Estimated **head-motion parameters** - the 6 rigid-body motion parameters (3 translations and 3 rotation), estimated relative to a reference image: 
 
@@ -40,7 +40,7 @@ While this *confound* file contains a large number of metrics, we have specific
 
 	* global_signal - the average signal within the brain mask.
 
-* **Count of motion outliers** - Scans occuring at times of particularly high motion are flagged by the motion\_outlierXX column. For summary, we want the count of 'motion_outliers' (or equally, the largest XX).  
+* **Count of motion outliers** - Scans occurring at times of particularly high motion are flagged by the motion\_outlierXX column. For summary, we want the count of 'motion_outliers' (or equally, the largest XX).  
 
 ### The Summariser Tool
 Given a pointer to a nibabies result directory, find each functional run, and create a table that aggregates the following content:

SumarizeNibabies.sh

@@ -15,15 +15,15 @@ outpt_file=$2
 
 echo "Processing the $inpt_dir for nibabies summarization and writing the output to $outpt_file"
 
-# Check for existance of input directory
+# Check for existence of input directory
 if [ -d $inpt_dir ]; then
     echo 'Input Directory exists, let us forge ahead'
 else
     echo 'Input Directory does not exist, we can no longer go on like this...'
     exit 20
 fi
 
-# Check for nonexistance of output file
+# Check for nonexistence of output file
 if [ -f $outpt_file ]; then
     echo 'Output file exists, let us stop'
 	exit 30
@@ -190,7 +190,7 @@ for f in ` find ${inpt_dir} -iname "*confounds_timeseries.tsv" `  ; do
 done
 
 # Display number of results proessed
-echo "We pocessed $COUNTER files, hooray!"
+echo "We processed $COUNTER files, hooray!"