Add page for LSP troubleshooting (#5554)

## Description

Adds a doc page for troubleshooting LSP. If users report an issue with
LSP, we can direct them here to save time.

## Checklist

- [ ] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [ ] I have requested a review from the relevant team or maintainers.

Author: sdankel

docs/book/src/SUMMARY.md

@@ -54,6 +54,7 @@
 - [Sway LSP](./lsp/index.md)
   - [Installation](./lsp/installation.md)
   - [Features](./lsp/features.md)
+  - [Troubleshooting](./lsp/troubleshooting.md)
 - [Sway Reference](./reference/index.md)
   - [Compiler Intrinsics](./reference/compiler_intrinsics.md)
   - [Attributes](./reference/attributes.md)

docs/book/src/lsp/index.md

@@ -12,3 +12,4 @@ Whether you are a beginner or an experienced Sway developer, this documentation
 
 - [Installation](./installation.md)
 - [Features](./features.md)
+- [Troubleshooting](./troubleshooting.md)

docs/book/src/lsp/troubleshooting.md

@@ -0,0 +1,29 @@
+# Troubleshooting
+
+First, confirm you are running the most recent version:
+
+```sh
+fuelup toolchain install latest
+fuelup update
+forc-lsp --version
+```
+
+Second, confirm that your `$PATH` resolves to the `forc-lsp` binary in `$HOME/.fuelup/bin`.
+
+```sh
+which forc-lsp
+```
+
+## Server Logs
+
+You can you enable verbose logging of the LSP server.
+
+In VSCode, this is under the setting:
+
+```json
+"sway-lsp.trace.server": "verbose"
+```
+
+Once enabled, you can find this in the output window under Sway Language Server.
+
+For other editors, see [Installation](./installation.md) for links to documentation.