Add pprof instruction to BUILD.md

BUILD.md

@@ -24,13 +24,22 @@ make build
 make release
 ```
 
-> :warning: Makefile uses git commands to determine the version and the
-> revision information for `fzf --version`. So if you're building fzf from an
+> [!WARNING]
+> Makefile uses git commands to determine the version and the revision
+> information for `fzf --version`. So if you're building fzf from an
 > environment where its git information is not available, you have to manually
 > set `$FZF_VERSION` and `$FZF_REVISION`.
 >
 > e.g. `FZF_VERSION=0.24.0 FZF_REVISION=tarball make`
 
+> [!TIP]
+> To build fzf with profiling options enabled, set `TAGS=pprof`
+>
+> ```sh
+> TAGS=pprof make clean install
+> fzf --profile-cpu /tmp/cpu.pprof
+> ```
+
 Third-party libraries used
 --------------------------