Add config to add custom text in the footer

Co-authored-by: Aural Glow <125497673+auralglow@users.noreply.github.com>

src/invidious/config.cr

@@ -106,6 +106,8 @@ class Config
   property cache_annotations : Bool = false
   # Optional banner to be displayed along top of page for announcements, etc.
   property banner : String? = nil
+  # Optional footer text to be displayed within Invidious' footer. Can be used for maintainer contact info, etc.
+  property footer : String? = nil
   # Enables 'Strict-Transport-Security'. Ensure that `domain` and all subdomains are served securely
   property hsts : Bool? = true
   # Disable proxying server-wide: options: 'dash', 'livestreams', 'downloads', 'local'

src/invidious/views/template.ecr

@@ -139,9 +139,14 @@
         <div class="pure-u-1 pure-u-md-2-24"></div>
         <div class="h-box pure-u-1 pure-u-md-20-24" id="footer-content-container">
             <div class="pure-u-1 footer-content">
-                <div class="footer-section pure-u-1-4" id="about-invidious-description">
+                <div class="footer-section pure-u-1-4" id="footer-custom-text">
                     <b>Invidious</b>
-                    <p><%=translate(locale, "footer_invidious_project_description")%></p>
+                    <% if CONFIG.footer %>
+                        <p><%=CONFIG.footer%></p>
+                    <% else %>
+                        <p><%=translate(locale, "default_invidious_footer_text")%></p>
+                    <% end %>
+                    
                 </div>
                 <div class="footer-section">
                     <b class="footer-section-header"><%= translate(locale, "footer_navigation_section_header")%></b>