feat: add pagination in tag posts (#201)

* feat: add pagination in tag posts

Implement pagination in tag posts. Refactor and extract pagination logic and pagination component.

Closes: #152

* fix: update breadcrumbs for updated tag pagination

src/components/Breadcrumbs.astro

@@ -10,6 +10,18 @@ const breadcrumbList = currentUrlPath.split("/").slice(1);
 // replace Posts with Posts (page number)
 breadcrumbList[0] === "posts" &&
   breadcrumbList.splice(0, 2, `Posts (page ${breadcrumbList[1] || 1})`);
+
+// if breadcrumb is Home > Tags > [tag] > [page] <etc>
+// replace [tag] > [page] with [tag] (page number)
+breadcrumbList[0] === "tags" &&
+  !isNaN(Number(breadcrumbList[2])) &&
+  breadcrumbList.splice(
+    1,
+    3,
+    `${breadcrumbList[1]} ${
+      Number(breadcrumbList[2]) === 1 ? "" : "(page " + breadcrumbList[2] + ")"
+    }`
+  );
 ---
 
 <nav class="breadcrumb" aria-label="breadcrumb">