Reword the second paragraph of introduction chapter

Closes: #15
Signed-off-by: Anup Patel <[email protected]>

src/intro.adoc

@@ -8,17 +8,18 @@ functions. This allows for diagnostics, interaction and measurement of
 a target system without requiring significant infrastructure to exist
 in that target environment.
 
-The RISC-V semihosting specification adapts the design of the publicly available
-and open source semihosting specification cite:[ARMSemihostingRef] to minimize
-the development effort. Only the mechanism of invoke a semihosting service
-(aka semihosting binary interface) is architecture specific whereas all defined
-semihosting services cite:[ARMSemihostingRef] are architecture independent and
-resemble system calls of an unix-style operating system. The <<fig_intro1>>
-below shows an architecture independent high-level view of semihosting usage.
+The RISC-V semihosting specification adopts the design of the publicly
+available and open source semihosting specification cite:[ARMSemihostingRef]
+to minimize the development effort. The semihosting services defined by
+the open source semihosting specification cite:[ARMSemihostingRef] are
+portable across different architectures, and only the mechanism of
+invoking a semihosting service (aka semihosting binary interface) is
+archicture specific. The <<fig_intro1>> below shows an architecture
+independent high-level view of semihosting usage.
 
-This specification only defines the semihosting binary interface for RISC-V
-platforms and all other aspects of semihosting are defined by the open source
-semihosting specification cite:[ARMSemihostingRef].
+The RISC-V semihosting specification only defines the semihosting binary
+interface for RISC-V platforms and all other aspects of semihosting are
+defined by the open source semihosting specification cite:[ARMSemihostingRef].
 
 [#fig_intro1]
 .Generic Semihosting Usage Flow