Remove do-targets and redundant use-cases from KLayout docs

Address PR review: do-targets are internal to bazel-orfs and
don't need user-facing documentation. Use-cases table is
redundant with the introductory paragraph.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

Author: oharboe

flow/docs/KLayoutOptionalDependency.md

@@ -11,8 +11,6 @@ without KLayout installed.
 |---|---|---|
 | `make finish` | No | Complete flow through timing reports |
 | `make gds` | Yes | Generate GDS/OAS from finished design |
-| `make do-finish` / `make do-final` | No | Same as `finish`, for bazel-orfs |
-| `make do-gds` | Yes | Same as `gds`, for bazel-orfs |
 | `make drc` | Yes | Run DRC checks (requires GDS) |
 | `make lvs` | Yes | Run LVS checks (requires GDS) |
 | `make gallery` | Yes | Generate layout screenshots |
@@ -27,19 +25,6 @@ Error: KLayout not found. Install KLayout or set KLAYOUT_CMD.
 Hint: 'make finish' works without KLayout. Only GDS/DRC/LVS need it.
 ```
 
-## Use Cases
-
-| Use Case | Needs KLayout? |
-|---|---|
-| Education / learning digital design | No |
-| Architectural exploration (PPA analysis) | No |
-| CI testing of ORFS / OpenROAD | No |
-| Local ORFS and OpenROAD development | No |
-| bazel-orfs default `orfs_flow()` | No |
-| GDS generation for tapeout | Yes |
-| DRC / LVS verification | Yes |
-| Layout visualization in KLayout GUI | Yes |
-
 ## bazel-orfs Integration
 
 bazel-orfs uses the `do-` prefixed targets which bypass Make's dependency