dape: Theme dape-adapter-dir

dape is a DAP client for Emacs.

At the time of writing, `dape-adapter-dir`, which is meant to be a
dumping ground for user-downloaded debug adapters, is the only
configuration file it defines.

dape-adapter-dir is not automatically created by dape.el; users
are expected to create dape-adapter-dir themselves before they
manually put their debug adapters there (unlike with dap-mode,
dape does not offer to download adapters for the user).

no-littering.el

@@ -218,6 +218,7 @@ This variable has to be set before `no-littering' is loaded.")
     (setq dap-breakpoints-file             (var "dap/breakpoints.el"))
     (setq dap-java-test-runner             (var "lsp-java/eclipse.jdt.ls/test-runner/junit-platform-console-standalone.jar"))
     (setq dap-utils-extension-path         (var "dap/extensions/"))
+    (setq dape-adapter-dir                 (var "dape-adapters/"))
     (setq debbugs-gnu-persistency-file     (var "debbugs.el"))
     (setq detached-db-directory            (var "detached/db/"))
     (setq detached-session-directory       (var "detached/sessions/"))
@@ -356,6 +357,7 @@ This variable has to be set before `no-littering' is loaded.")
     (eval-after-load 'bookmark+-1 `(make-directory ,(var "bmkp/") t))
     (eval-after-load 'command-log-mode '(make-directory clm/logging-dir t))
     (eval-after-load 'company     `(make-directory ,(var "company/") t))
+    (eval-after-load 'dape        '(make-directory dape-adapter-dir t))
     (eval-after-load 'elfeed      `(make-directory ,(var "elfeed/") t))
     (eval-after-load 'emojify     '(make-directory emojify-emojis-dir t))
     (eval-after-load 'geiser      `(make-directory ,(var "geiser/") t))