docs(support): add contact@sablier.com support channel

- New Contact Us page under docs/support listing email, Discord, and GitHub
- Add Contact mailto link to footer Company column

Author: PaulRBerg

config/theme-config.ts

@@ -15,6 +15,10 @@ const footer: Preset.ThemeConfig["footer"] = {
           href: "https://sablierlabs.co.uk",
           label: "About",
         },
+        {
+          href: "mailto:contact@sablier.com",
+          label: "Contact",
+        },
         {
           href: "https://files.sablier.com/risk-notice.pdf",
           label: "Risk Notice",

docs/support/04-contact.mdx

@@ -0,0 +1,28 @@
+---
+id: "contact"
+sidebar_position: 4
+title: "Contact Us"
+---
+
+If you need help with the Sablier protocols, the apps, or anything else, you can reach us through any of the following
+channels.
+
+## Email
+
+For customer support, partnership inquiries, or anything that doesn't fit a public channel, email us at
+[contact@sablier.com](mailto:contact@sablier.com).
+
+We typically reply within one business day.
+
+## Discord
+
+For real-time questions and community discussion, join our [Discord server](https://discord.sablier.com). The team and
+community members are active there and happy to help.
+
+- `#support` — for help with the apps and protocols
+- `#dev` — for integration and smart contract questions
+
+## GitHub
+
+If you've found a bug or want to request a feature, open an issue in the relevant repository under the
+[`sablier-labs`](https://github.com/sablier-labs) organization on GitHub.