add necroscans (#4136)

src/en/necroscans/build.gradle

@@ -0,0 +1,9 @@
+ext {
+    extName = 'Necro Scans'
+    extClass = '.NecroScans'
+    themePkg = 'keyoapp'
+    baseUrl = 'https://necroscans.com'
+    overrideVersionCode = 0
+}
+
+apply from: "$rootDir/common.gradle"

src/en/necroscans/src/eu/kanade/tachiyomi/extension/en/necroscans/NecroScans.kt

@@ -0,0 +1,5 @@
+package eu.kanade.tachiyomi.extension.en.necroscans
+
+import eu.kanade.tachiyomi.multisrc.keyoapp.Keyoapp
+
+class NecroScans : Keyoapp("Necro Scans", "https://necroscans.com", "en")