Add an editorconfig and use 4 spaces indent

.editorconfig

@@ -0,0 +1,11 @@
+root = true
+
+[*]
+charset = utf-8
+insert_final_newline = true
+end_of_line = lf
+indent_style = space
+max_line_length = 80
+
+[*.ts]
+indent_size = 4

index.ts

@@ -1,36 +1,36 @@
 import { getInput, getMultilineInput, setFailed } from "@actions/core";
 
 function parseJsonInput(param_name: string) {
-  const param_val = getInput(param_name);
-  try {
-    return JSON.parse(param_val);
-  } catch (error) {
-    throw new Error(
-      `Invalid '${param_name}' input ${param_val}: ${(error as Error).message}`,
-    );
-  }
+    const param_val = getInput(param_name);
+    try {
+        return JSON.parse(param_val);
+    } catch (error) {
+        throw new Error(
+            `Invalid '${param_name}' input ${param_val}: ${(error as Error).message}`,
+        );
+    }
 }
 
 function main() {
-  const needs = parseJsonInput("needs");
-  const skippable = getMultilineInput("skippable");
+    const needs = parseJsonInput("needs");
+    const skippable = getMultilineInput("skippable");
 
-  console.debug(`needs: ${JSON.stringify(needs)}`);
-  console.debug(`skippable: ${JSON.stringify(skippable)}`);
-  for (const job_id of Object.keys(needs)) {
-    const result = needs[job_id].result;
-    console.log(`Job ${job_id} returned ${result}`);
-    if (result == "skipped" && skippable.includes(job_id)) {
-      continue;
-    }
-    if (result != "success") {
-      throw new Error(`Job ${job_id} returned ${result}`);
+    console.debug(`needs: ${JSON.stringify(needs)}`);
+    console.debug(`skippable: ${JSON.stringify(skippable)}`);
+    for (const job_id of Object.keys(needs)) {
+        const result = needs[job_id].result;
+        console.log(`Job ${job_id} returned ${result}`);
+        if (result == "skipped" && skippable.includes(job_id)) {
+            continue;
+        }
+        if (result != "success") {
+            throw new Error(`Job ${job_id} returned ${result}`);
+        }
     }
-  }
 }
 
 try {
-  main();
+    main();
 } catch (error) {
-  setFailed((error as Error).message);
+    setFailed((error as Error).message);
 }