private void getConfigKeyRst(ConfigKey key, StringBuilder b) {
        b.append("``").append(key.name).append("``").append("\n");
        if (key.documentation != null) {
            for (String docLine : key.documentation.split("\n")) {
                if (docLine.length() == 0) {
                    continue;
                }
                b.append("  ").append(docLine).append("\n\n");
            }
        } else {
            b.append("\n");
        }
        b.append("  * Type: ").append(getConfigValue(key, "Type")).append("\n");
        if (key.hasDefault()) {
            b.append("  * Default: ").append(getConfigValue(key, "Default")).append("\n");
        }
        if (key.validator != null) {
            b.append("  * Valid Values: ").append(getConfigValue(key, "Valid Values")).append("\n");
        }
        b.append("  * Importance: ").append(getConfigValue(key, "Importance")).append("\n");
    }
Shared content on Rst and Enriched Rst.
clients/src/main/java/org/apache/kafka/common/config/ConfigDef.java