fix ShellCheck warnings and add workflow for test

ShellCheck previously reported:

```
In please.sh line 123:
  response=(${response[@]})
            ^------------^ SC2206: Quote to prevent word splitting/globbing, or split robustly with mapfile or read -a.

In please.sh line 125:
  result=${response[@]::${#response[@]}-1}
         ^-- SC2124: Assigning an array to a string! Assign as array, or use * instead of @ to concatenate.

In please.sh line 137:
  printf "${lightbulb}${cyan}Command:${black}\n"
         ^-- SC2059: Don't use variables in the printf format string. Use printf "..%s.." "$foo".

In please.sh line 144:
  printf "${exclamation} ${yellow}What should I do? ${cyan}[use arrow keys to navigate]${black}\n"
         ^-- SC2059: Don't use variables in the printf format string. Use printf "..%s.." "$foo".

For more information:
  https://www.shellcheck.net/wiki/SC2124 -- Assigning an array to a string! A...
  https://www.shellcheck.net/wiki/SC2206 -- Quote to prevent word splitting/g...
  https://www.shellcheck.net/wiki/SC2059 -- Don't use variables in the printf...
```

`result=${response[@]::${#response[@]}-1}` is not needed
as `echo "${result}" | jq '.choices[0].message.content' --raw-output`
will anyhow only consider the first element of `response`.

Signed-off-by: Manfred Hanke <[email protected]>

.github/workflows/test.yml

@@ -0,0 +1,16 @@
+name: Test Please CLI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  shellcheck:
+    name: Shellcheck
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Run ShellCheck
+        uses: ludeeus/action-shellcheck@master

please.sh

@@ -124,33 +124,33 @@ explain_command() {
 }
 
 perform_openai_request() {
-  response=$(curl "${openai_invocation_url}/chat/completions" \
+  IFS=$'\n' read -r -d '' -a response < <(curl "${openai_invocation_url}/chat/completions" \
        -s -w "\n%{http_code}" \
        -H "Content-Type: application/json" \
        -H "Authorization: Bearer ${OPENAI_API_KEY}" \
        -d "${payload}" \
        --silent)
-  response=(${response[@]})
   httpStatus="${response[${#response[@]}-1]}"
-  result=${response[@]::${#response[@]}-1}
 
   if [ "${httpStatus}" -ne 200 ]; then
     >&2 echo "Error: Received HTTP status ${httpStatus}"
     exit 1
   else
-    message=$(echo "${result}" | jq '.choices[0].message.content' --raw-output)
+    message=$(echo "${response[0]}" | jq '.choices[0].message.content' --raw-output)
     echo "${message}"
   fi
 }
 
 print_option() {
+  # shellcheck disable=SC2059
   printf "${lightbulb}${cyan}Command:${black}\n"
   echo "  ${command}"
   if [ "${explain}" -eq 1 ]; then
     echo ""
     echo "${explanation}"
   fi
   echo ""
+  # shellcheck disable=SC2059
   printf "${exclamation} ${yellow}What should I do? ${cyan}[use arrow keys to navigate]${black}\n"
 }