capi: Include blazesym.h in published package

Make sure to include the blazesym.h header file in the published
package, to make it easier to work with only the crates.io package, even
when building a C program.

Signed-off-by: Daniel Müller <deso@posteo.net>

capi/CHANGELOG.md

@@ -1,3 +1,8 @@
+Unreleased
+----------
+- Included `blazesym.h` header file in release package
+
+
 0.1.0-alpha.0
 -------------
 - Added constructs for forward & backward compatibility:

capi/Cargo.toml

@@ -22,7 +22,7 @@ keywords = [
   "stacktrace",
   "tracing",
 ]
-include = ["src/**/*", "!**/examples/**/*", "README.md", "CHANGELOG.md", "examples/input-struct-init.c", "build.rs"]
+include = ["src/**/*", "include/**/*", "!**/examples/**/*", "README.md", "CHANGELOG.md", "examples/input-struct-init.c", "build.rs"]
 autobenches = false
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html