Update files for javascript build and export

Adds some files to making building and export for HTML5 more convenient.

misc/docker/Dockerfile

@@ -0,0 +1,4 @@
+# For convenient building of the library and gdnative export templates targeted at the javacript platform.
+FROM emscripten/emsdk:2.0.10
+RUN apt-get update && apt-get install pkg-config python3 -y
+RUN pip3 install scons

misc/export_templates/build.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+set -e
+
+# Get the absolute path to the directory this script is in.
+EXPORT_TEMPLATES_DIR="$( cd "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P )"
+
+# Update git submodules.
+GODOT_DIR=${EXPORT_TEMPLATES_DIR}/godot
+if [ ! -d "$GODOT_DIR" ]; then
+	cd ${EXPORT_TEMPLATES_DIR}
+	git submodule update --init --recursive -- $GODOT_DIR
+fi
+
+# Use Docker to build HTML5 GDNative export templates.
+UID_GID="0:0" docker-compose build javascript
+
+# Debug
+UID_GID="$(id -u):$(id -g)" docker-compose run -e TARGET=debug javascript
+mv godot/bin/godot.javascript.debug.gdnative.zip godot/bin/webassembly_gdnative_debug.zip    
+
+### Release
+UID_GID="$(id -u):$(id -g)" docker-compose run -e TARGET=release javascript
+mv godot/bin/godot.javascript.opt.gdnative.zip godot/bin/webassembly_gdnative_release.zip

misc/export_templates/docker-compose.yaml

@@ -0,0 +1,12 @@
+services:
+  javascript:
+    build: ../docker
+    user: ${UID_GID}
+    volumes:
+      - ./godot:/src
+    command:
+      - /bin/bash
+      - -c
+      - |
+        cd src
+        scons platform=javascript tools=no gdnative_enabled=yes target=$${TARGET} -j$$(nproc)

misc/export_templates/readme.txt

@@ -0,0 +1 @@
+HTML5 GDNative export templates are not provided, this is just a convient script/docker-compose file for building them locally.