add .env.template to github tool

Signed-off-by: Maia Iyer <maia.raj.iyer@gmail.com>

Author: maia-iyer

mcp/github_tool/.env.template

@@ -0,0 +1,5 @@
+UPSTREAM_MCP = "https://api.githubcopilot.com/mcp/"
+REQUIRED_SCOPE = "github-full-access"
+INIT_AUTH_HEADER = "Bearer <PAT>"
+UPSTREAM_HEADER_TO_USE_IF_IN_AUDIENCE = "Bearer <PAT>"
+UPSTREAM_HEADER_TO_USE_IF_NOT_IN_AUDIENCE = "Bearer <PAT>"