Repository: dbt-labs/dbt-core
Pull request: include directory README
### resolves https://github.com/dbt-labs/dbt-core/issues/4968


### Description

Writing up a README for the include directory giving brief description of each folder or file in top level.

### Checklist

- [x] I have signed the [CLA](https://docs.getdbt.com/docs/contributor-license-agreements)
- [x] I have run this code in development and it appears to resolve the stated issue
- [x] This PR includes tests, or tests are not required/relevant for this PR
- [x] I have updated the `CHANGELOG.md` and added information about my change


Problem statement:
[CT-433] [docs] Add ReadMe to include directory
### Is there an existing feature request for this?

- [X] I have searched the existing issues

### Describe the Feature

adding ReadMe to directories to deepen knowledge of code base for all

### Describe alternatives you've considered

_No response_

### Who will this benefit?

everyone

### Are you interested in contributing this feature?

_No response_

### Anything else?

_No response_

Hints from issue discussion:

Commit message: minor updates

Patch to review:
diff --git a/core/dbt/include/README.md b/core/dbt/include/README.md
index 59670b67f7d..a6d6c391c1e 100644
--- a/core/dbt/include/README.md
+++ b/core/dbt/include/README.md
@@ -1 +1,10 @@
-# Include README
+# Include Module
+
+contains the a few key default `dbt-core` sub directories inlcuding.
+
+- `global_project` which defines the default implementations of jinja2 macros for `dbt-core ` which can be overwritten in each adapter repo to work more in line with those adapter plugins. to view adapter specific jinja2 changes please check the relevant adapter repo.
+
+- `starter_project` which produces the default init project inside the `dbt-core` project after doing the `make dev` command
+
+- A `index.html` file used to generate the docs page after using the `generate docs` command in dbt.
+


Code review comments:
diff_hunk: @@ -1 +1,10 @@
-# Include README
+# Include Module
+
+contains the a few key default `dbt-core` sub directories inlcuding.
+
+- `global_project` which defines the default implementations of jinja2 macros for `dbt-core ` which can be overwritten in each adapter repo to work more in line with those adapter plugins. to view adapter specific jinja2 changes please check the relevant adapter repo.
+
+- `starter_project` which produces the default init project inside the `dbt-core` project after doing the `make dev` command
+
+- A `index.html` file used to generate the docs page after using the `generate docs` command in dbt.
path: core/dbt/include/README.md
text: @user1:
Can we point out that `index.html` is actually built from the [dbt-docs](https://github.com/dbt-labs/dbt-docs) repo?  The `README` over there has details on how it's built.  And then that file is used when `docs generate` is run.

@user2:
And maybe mention that the index.html is generated by hand prior to a release?

@author:
I might need a bit more context for that @user2 I haven't had to deal with the dbt-docs so to what degree to we have to regenerate the project? prior to release not sure if we have a write up on that anywhere.

@user2:
Jeremy usually generated the file, but Emily did it last time. The file is created from the dbt-docs repo and copied here.

@author:
ah, okay interesting, now i'm curious to why we have to do it each release? is it just in case any name or ui changes we make? 

@user1:
@user3 is it not generated only when `dbt-docs` changes?  It just needs to be done prior to a release when changes occur since the file gets committed to `dbt-core`.

@user2:
We have sometimes changed attributes in core that dbt-docs depends on. So it needs to be generated for each release, to check that it works.

@author:
ah that's intriguing, will highlight that and try to have a new version up today.

@user4:
To clarify this point:
- `dbt-docs` depends on `manifest.json` + `catalog.json`, which are contracted/versioned
- Whenever the schema of those artifacts changes (in new minor versions), we always want to test that `index.html` still works / is compatible
- We only need to regenerate `index.html` if we've made changes to the `dbt-docs` source code (for compatibility with the new artifact schemas, to fix an unrelated bug, etc)

diff_hunk: @@ -1 +1,10 @@
-# Include README
+# Include Module
+
+contains the a few key default `dbt-core` sub directories inlcuding.
path: core/dbt/include/README.md
text: @user1:
There's a few typos here to fix.