fix(frontend): add missing docstrings

frontend/src/lib/components/data-table/utils.ts

@@ -1,3 +1,13 @@
+/**
+ * Replaces placeholders in a template string with values from a replacement items object.
+ *
+ * The placeholders are in the format %key%, whereby %key% is replaced with the value of the 'key'
+ * attribute in the replacementItems object.
+ *
+ * @param {string} templateString - The template string containing placeholders to be replaced.
+ * @param {object} replacementItems - The object containing key-value pairs for replacement.
+ * @returns {string} The modified string with all placeholders replaced.
+ */
 export function interpolateString(templateString: string, replacementItems: { [key: string]: any }): string {
   if (typeof templateString !== 'string') {
     return '';

frontend/src/lib/utils/markdown.ts

@@ -1,6 +1,13 @@
 import { marked } from 'marked';
 import dompurify from 'dompurify';
 
+/**
+ * Converts the input text, which is assumed to be in markdown format, into HTML and returns it.
+ * The returned HTML is sanitized to prevent XSS.
+ *
+ * @param {string} text - The input text in markdown format to convert.
+ * @returns {string} The HTML representation of the input text.
+ */
 export function markdownToHtml(text: string): string {
   // Remove zerowidth chars from beginning of input string
   // This is probably not necessary...