feat: add meta description to more pages

frontend/src/routes/@[username]/+page.svelte

@@ -252,6 +252,7 @@
     content={data.display_name ? `${data.display_name} (@${data.name})` : `@${data.name}`}
   />
   <meta property="og:url" content="{PUBLIC_BASE_URL}/@{data.name}" />
+  <meta name="description" content="@{data.name} on pronouns.cc" />
 
   {#if data.avatar}
     <meta property="og:image" content={userAvatars(data)[0]} />

frontend/src/routes/@[username]/[memberName]/+page.svelte

@@ -122,6 +122,7 @@
       : `${data.name} (@${data.user.name})`}
   />
   <meta property="og:url" content="{PUBLIC_BASE_URL}/@{data.user.name}/{data.name}" />
+  <meta name="description" content="{data.name} (@{data.user.name}) on pronouns.cc" />
 
   {#if data.avatar}
     <meta property="og:image" content={memberAvatars(data)[0]} />

frontend/src/routes/page/about/+page.svelte

@@ -4,6 +4,8 @@
 
 <svelte:head>
   <title>About & contact - pronouns.cc</title>
+  <meta name="description" content="pronouns.cc's about and contact page" />
+  <meta property="og:description" content="pronouns.cc's about and contact page" />
 </svelte:head>
 
 <div class="grid">

frontend/src/routes/page/privacy/+page.svelte

@@ -4,6 +4,8 @@
 
 <svelte:head>
   <title>Privacy policy - pronouns.cc</title>
+  <meta name="description" content="pronouns.cc's privacy policy" />
+  <meta property="og:description" content="pronouns.cc's privacy policy" />
 </svelte:head>
 
 <div class="grid">

frontend/src/routes/page/terms/+page.svelte

@@ -4,6 +4,8 @@
 
 <svelte:head>
   <title>Terms of service - pronouns.cc</title>
+  <meta name="description" content="pronouns.cc's terms of service" />
+  <meta property="og:description" content="pronouns.cc's terms of service" />
 </svelte:head>
 
 <div class="grid">