feat:ReplyByEmail button

Add documentation for the component

docs/features/replybyemail button.md

@@ -0,0 +1,67 @@
+---
+title: Reply by Email Button
+tags:
+  - component
+---
+
+The Reply By Email Button is a feature that allows users to display a button under their notes, allowing visitors to send them an email to an obfuscated email address.  
+- The email address is base64 encoded to provide some basic protection from bots.
+- The subject line of the email will be taken from the page Title where the button is clicked.
+- You can specify on what notes the button should be displayed or excluded.
+- The label on the button can also be customised.
+
+## Configuration
+
+The Reply By Email Button is disabled by default. To enable it, you can add the component to your layout configuration in `quartz.layout.ts`.
+
+Minimal configuration:
+```ts
+Component.ReplyByEmail({
+  username: "Y29udGFjdA==", // "contact" encoded in base64, as in contact@example.com
+  domain: "ZXhhbXBsZS5jb20=", // "example.com" encoded in base64, as in contact@example.com
+}),
+```
+You can specify under which notes to display the button by adding the following:
+```ts
+includeTitles: ["Welcome to Quartz 4", "Reply by Email Button"],
+```
+Alternatively, you can include the button by default by ommiting the `includeTitles` line, and specify notes under which the button should not be displayed:
+```ts
+excludeTitles: ["Welcome to Quartz 4", "Home"],
+```
+You can also override the default `buttonLabel` text:
+```ts
+buttonLabel: "Reply by email"
+```
+
+
+## Usage
+
+The natural placement for the Reply By Email Button is within `afterBody` in the Content Pages, so that it is displayed right under the note:
+
+```ts
+  afterBody: [
+    Component.ReplyByEmail({
+      username: "Y29udGFjdA==", // "contact" encoded in base64, as in contact@example.com
+      domain: "ZXhhbXBsZS5jb20=", // "example.com" encoded in base64, as in contact@example.com
+      // includeTitles: ["Welcome to Quartz 4"], // You can specify which page titles to include or comment out the line to include on all pages
+      excludeTitles: ["Welcome to Quartz 4", "Home"],  // You can specify which page titles to exclude when includeTitles is empty
+      buttonLabel: "Submit feedback by email" // You can override the default button text "Reply by email"
+    }),
+  ],
+```
+
+## Customization
+
+You can customize the appearance of the ReplyByEmail button through CSS variables and styles. The component uses the following class:
+
+- `.reply-by-email-button`
+
+
+Example customization in your custom CSS:
+
+```scss
+.reply-by-email-button {
+  color: var(--tertiary);
+}
+```