Replace "." for ":" the lines that were missing it before code blocks.

docs/topics/basic-syntax.md

@@ -8,7 +8,7 @@ by JetBrains Academy.
 
 ## Package definition and imports
 
-Package specification should be at the top of the source file.
+Package specification should be at the top of the source file:
 
 ```kotlin
 package my.demo
@@ -24,7 +24,7 @@ See [Packages](packages.md).
 
 ## Program entry point
 
-An entry point of a Kotlin application is the `main` function.
+An entry point of a Kotlin application is the `main` function:
 
 ```kotlin
 fun main() {
@@ -33,7 +33,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-hello-world"}
 
-Another form of `main` accepts a variable number of `String` arguments. 
+Another form of `main` accepts a variable number of `String` arguments: 
 
 ```kotlin
 fun main(args: Array<String>) {
@@ -44,7 +44,7 @@ fun main(args: Array<String>) {
 
 ## Print to the standard output
 
-`print` prints its argument to the standard output.
+`print` prints its argument to the standard output:
 
 ```kotlin
 fun main() {
@@ -56,7 +56,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-print"}
 
-`println` prints its arguments and adds a line break, so that the next thing you print appears on the next line.
+`println` prints its arguments and adds a line break, so that the next thing you print appears on the next line:
 
 ```kotlin
 fun main() {
@@ -70,7 +70,7 @@ fun main() {
 
 ## Functions
 
-A function with two `Int` parameters and `Int` return type.
+A function with two `Int` parameters and `Int` return type:
 
 ```kotlin
 //sampleStart
@@ -86,7 +86,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-return-int"}
 
-A function body can be an expression. Its return type is inferred.
+A function body can be an expression. Its return type is inferred:
 
 ```kotlin
 //sampleStart
@@ -99,7 +99,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-function-expression"}
 
-A function that returns no meaningful value.
+A function that returns no meaningful value:
 
 ```kotlin
 //sampleStart
@@ -114,7 +114,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-return-unit"}
 
-`Unit` return type can be omitted.
+`Unit` return type can be omitted:
 
 ```kotlin
 //sampleStart
@@ -229,20 +229,20 @@ For information about declaring properties, see [Properties](properties.md).
 
 ## Creating classes and instances
 
-To define a class, use the `class` keyword.
+To define a class, use the `class` keyword:
 ```kotlin
 class Shape
 ```
 
-Properties of a class can be listed in its declaration or body. 
+Properties of a class can be listed in its declaration or body: 
 
 ```kotlin
 class Rectangle(val height: Double, val length: Double) {
     val perimeter = (height + length) * 2 
 }
 ```
 
-The default constructor with parameters listed in the class declaration is available automatically. 
+The default constructor with parameters listed in the class declaration is available automatically:
 
 ```kotlin
 class Rectangle(val height: Double, val length: Double) {
@@ -258,7 +258,7 @@ fun main() {
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-class-constructor"}
 
 Inheritance between classes is declared by a colon (`:`). Classes are final by default; to make a class inheritable, 
-mark it as `open`.
+mark it as `open`:
 
 ```kotlin
 open class Shape
@@ -272,7 +272,7 @@ See [classes](classes.md) and [objects and instances](object-declarations.md).
 
 ## Comments
 
-Just like most modern languages, Kotlin supports single-line (or _end-of-line_) and multi-line (_block_) comments.
+Just like most modern languages, Kotlin supports single-line (or _end-of-line_) and multi-line (_block_) comments:
 
 ```kotlin
 // This is an end-of-line comment
@@ -281,7 +281,7 @@ Just like most modern languages, Kotlin supports single-line (or _end-of-line_)
    on multiple lines. */
 ```
 
-Block comments in Kotlin can be nested.
+Block comments in Kotlin can be nested:
 
 ```kotlin
 /* The comment starts here
@@ -330,7 +330,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-conditional-expressions"}
 
-In Kotlin, `if` can also be used as an expression.
+In Kotlin, `if` can also be used as an expression:
 
 ```kotlin
 //sampleStart
@@ -359,7 +359,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-for-loop"}
 
-or
+or:
 
 ```kotlin
 fun main() {
@@ -421,7 +421,7 @@ See [when expression](control-flow.md#when-expression).
 
 ## Ranges
 
-Check if a number is within a range using `in` operator.
+Check if a number is within a range using `in` operator:
 
 ```kotlin
 fun main() {
@@ -436,7 +436,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-range-in"}
 
-Check if a number is out of range.
+Check if a number is out of range:
 
 ```kotlin
 fun main() {
@@ -454,7 +454,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-out-of-range"}
 
-Iterate over a range.
+Iterate over a range:
 
 ```kotlin
 fun main() {
@@ -467,7 +467,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-iterate-range"}
 
-Or over a progression.
+Or over a progression:
 
 ```kotlin
 fun main() {
@@ -488,7 +488,7 @@ See [Ranges and progressions](ranges.md).
 
 ## Collections
 
-Iterate over a collection.
+Iterate over a collection:
 
 ```kotlin
 fun main() {
@@ -578,7 +578,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-function-nullable-value"}
 
-or
+or:
 
 ```kotlin
 fun parseInt(str: String): Int? {
@@ -644,7 +644,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-is-operator"}
 
-or
+or:
 
 ```kotlin
 //sampleStart
@@ -667,7 +667,7 @@ fun main() {
 ```
 {kotlin-runnable="true" kotlin-min-compiler-version="1.3" id="kotlin-basic-syntax-is-operator-expression"}
 
-or even
+or even:
 
 ```kotlin
 //sampleStart