Move bdk-jvm and bdk-android out of subdirectory after ffi merge

bdk-jvm/plugins/README.md

@@ -0,0 +1,16 @@
+# Readme
+The purpose of this directory is to host the Gradle plugin that adds tasks for building the native binaries required by bdk-jvm, and building the language bindings files.
+
+The plugin is applied to the `build.gradle.kts` file through the `plugins` block:
+```kotlin
+plugins {
+    id("org.bitcoindevkit.plugin.generate-jvm-bindings")
+}
+```
+
+The plugin adds a series of tasks which are brought together into an aggregate task called `buildJvmLib` for `bdk-jvm`. 
+
+This aggregate task:
+1. Builds the native library(ies) using `bdk-ffi`
+2. Places it in the correct resource directory
+3. Builds the bindings file