feat(learn): Create tool to delete an existing project step in project-based curriculum (#39786)

* feat: created tool to delete step

* docs: update README.md with delete-step instructions

Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>

tools/challenge-helper-scripts/delete-step.js

@@ -0,0 +1,35 @@
+const fs = require('fs');
+
+const {
+  reorderSteps,
+  padWithLeadingZeros,
+  getExistingStepNums,
+  getProjectPath,
+  getArgValues
+} = require('./utils');
+
+const stepExists = (steps, stepToFind) => steps.includes(stepToFind);
+
+const projectPath = getProjectPath();
+const args = getArgValues(process.argv);
+
+let { num } = args;
+num = parseInt(num, 10);
+
+if (!Number.isInteger(num) || num < 1) {
+  throw 'Step not deleted. Step num must be a number greater than 0.';
+}
+
+const existingSteps = getExistingStepNums(projectPath);
+if (!stepExists(existingSteps, num)) {
+  throw `Step # ${num} not deleted because it does not exist.`;
+}
+
+const stepFileToDelete = `${projectPath}part-${padWithLeadingZeros(num)}.md`;
+try {
+  fs.unlinkSync(stepFileToDelete);
+  console.log(`Sucessfully deleted step #${num}`);
+  reorderSteps();
+} catch (err) {
+  console.error(err);
+}