feat: Add corner arrow icons

Closes #62

icons/arrows/corner-down-left.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="9 10 4 15 9 20" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M20 4v7a4 4 0 0 1-4 4H4" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>

icons/arrows/corner-down-right.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="15 10 20 15 15 20" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M4 4v7a4 4 0 0 0 4 4h12" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>

icons/arrows/corner-left-down.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="14 15 9 20 4 15" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M20 4h-7a4 4 0 0 0-4 4v12" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>

icons/arrows/corner-left-up.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="14 9 9 4 4 9" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M20 20h-7a4 4 0 0 1-4-4V4" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>

icons/arrows/corner-right-down.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="10 15 15 20 20 15" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M4 4h7a4 4 0 0 1 4 4v12" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>

icons/arrows/corner-right-up.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="10 9 15 4 20 9" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M4 20h7a4 4 0 0 0 4-4V4" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>

icons/arrows/corner-up-left.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="9 14 4 9 9 4" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M20 20v-7a4 4 0 0 0-4-4H4" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>

icons/arrows/corner-up-right.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+    <polyline points="15 14 20 9 15 4" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+    <path d="M4 20v-7a4 4 0 0 1 4-4h12" fill="none" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"/>
+</svg>