feat: nested submodules, S3 retries (#1360)

Bring in cdklabs/jsii-docgen#1215 which adds
support for nested submodules (`asm.sub1.sub2`), and adjust the code to
match.

Also add S3 throttling protection via retries and backoff, since we have
a fair bit of that going around as well.


----

*By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license*

.projenrc.ts

@@ -59,7 +59,6 @@ const project = new CdklabsConstructLibrary({
     'fs-extra',
     'got',
     'JSONStream',
-    'jsii-reflect',
     'semver',
     'spdx-license-list',
     'streamx',
@@ -198,6 +197,10 @@ project.addTask('bundle', {
   description: 'Bundle all lambda and ECS functions',
 });
 
+// I have to put this here, otherwise projen overrides this with a `jsii-docgen`
+// dependency without a version. I don't know where or why.
+project.addDevDeps('jsii-docgen@^10.2.0');
+
 // extract the "build/" directory from "construct-hub-webapp" into "./website"
 // and bundle it with this library. this way, we are only taking a
 // dev-dependency on the webapp instead of a normal/bundled dependency.