Add rocksdb compile error help (#563)

* Add minor document fixes

- fix broken link
- fix shell command formatting
- fix typo

* Add FAQ entry dealing with rocksdb

When compiling Grin without Linux headers the build process exits with
an opaque error message. Adding the header files fixes this.

References #549.

doc/FAQ.md

@@ -23,7 +23,7 @@
 Like other cryptocurrencies, newly mined coins are time locked, so mined coins can't be spent immediately.
 
 ## "Peer request error" or other peer/network issues after restarting grin server
-Possible workaround is rm -rf .grin/peers/*  then restart.
+Possible workaround is `rm -rf .grin/peers/*`  then restart.
 
 ## grin server or waller crashes or hangs
 Yes, this still happens quite often. You'll need to babysit grin.
@@ -36,11 +36,15 @@ Use `rustup` to [reinstall rust and cargo as described](build.md).
 
 NOTE: If you install rust or cargo with your package manager (most Linuxes
 anno 2017) you'll get too old versions. On Debian, you might have to manually
-compile cmake or get it from non-detault repositories.
+compile cmake or get it from non-default repositories.
 
 ## Build error: `failed to select a version for 'serde_json'`
 Run `cargo update` to fix this
 
+## Build error: Panic during rocksdb compilation.
+This is caused by missing Linux headers. Install the development headers with
+your favorite package manager (usually they are called `linux-headers`).
+
 # Short term plans
 ## Transaction types
 - (DONE) A temporary simple transaction exchange. Temporary - will be deprecated.

doc/build.md

@@ -42,7 +42,7 @@ git checkout milestone/testnet1
 cargo build
 ```
 ## Build errors
-See [Troubleshooting](faq.md#troubleshooting)
+See [Troubleshooting](FAQ.md#troubleshooting)
 
 #### Cross-compiling