vscode: add minimal configuration

It is essential to configure VSCode indexer plugins to ignore the build
folder of bitbake. Otherwise, the indexer plugins run with 100% CPU load
until an OOM exception occurs. In practice, this makes VSCode more or
less unusable for working with Yocto until a file like the one added by
this commit is deployed before VSCode starts. From the user's point of
view, it is not obvious why the system runs at 100% CPU load and
eventually crashes.

It is even more misleading that VSCode starts the indexers immediately,
but does not stop or reconfigure them when the ignore list is updated.
In practice, this means that every time the ignore list is changed,
VSCode immediately starts indexing the build folder until the OOM
exception stops it. Depending on the system's OOM handler, the entire
build machine may crash.
Particularly annoying is the Python plugin that ignores the general
ignore list and requires an extra ignore section.

The settings are suitable for workflows like bitbake, devtool modify,
devtool reset. The settings are not intended to work on the source code
of a recipe. It is assumed that a separate instance of VSCode is used
per workspace folder. These per workspace instances can have different
settings depending on the details of the sources that come with the
recipe.

VSCode can change the contents of the .vscode folder, which often leads
to a dirty git status. Normally, these changes are not added to git.
Otherwise, -f can be used to add them explicitly. It is not perfect if
the folder is listed in .gitignore. But it is also not better if it is
not.

(From OE-Core rev: 52cff14a73c9f286da4f627dc1aabf5c80aee63d)

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

.gitignore

@@ -36,3 +36,5 @@ _toaster_clones/
 downloads/
 sstate-cache/
 toaster.sqlite
+.vscode/
+vscode-bitbake-build/

.vscode/settings.json

@@ -0,0 +1,32 @@
+{
+    "files.watcherExclude": {
+        "**/.git/**": true,
+        "**/cache/**": true,
+        "**/tmp*/**": true,
+        "**/downloads/**": true,
+        "**/sstate-cache/**": true,
+        "**/vscode-bitbake-build/**": true,
+        "**/workspace/sources/**": true,
+        "**/workspace/attic/**": true
+    },
+    "files.exclude": {
+        "**/.git/**": true,
+        "**/cache/**": true,
+        "**/tmp*/**": true,
+        "**/downloads/**": true,
+        "**/sstate-cache/**": true,
+        "**/vscode-bitbake-build/**": true,
+        "**/workspace/sources/**": true,
+        "**/workspace/attic/**": true
+    },
+    "python.analysis.exclude": [
+        "**/.git/**",
+        "**/cache/**",
+        "**/tmp*/**",
+        "**/downloads/**",
+        "**/sstate-cache/**",
+        "**/vscode-bitbake-build/**",
+        "**/workspace/sources/**",
+        "**/workspace/attic/**"
+    ]
+}