Start Gleam snippets with tab character

All other snippet files are doing this, and if it is not done at least
UltiSnips complains about malformed snippet lines.

Author: Alexey Vyskubov

snippets/gleam.snippets

@@ -1,98 +1,98 @@
 snippet fn "fn"
-  fn ${1:function_name}(${2}) -> ${3:Nil} {
-    ${0:${VISUAL:todo}}
-  }
+	fn ${1:function_name}(${2}) -> ${3:Nil} {
+	  ${0:${VISUAL:todo}}
+	}
 
 snippet pfn "pub fn"
-  pub fn ${1:function_name}(${2}) -> ${3:Nil} {
-    ${0:${VISUAL:todo}}
-  }
+	pub fn ${1:function_name}(${2}) -> ${3:Nil} {
+	  ${0:${VISUAL:todo}}
+	}
 
 snippet test "test fn"
-  pub fn ${1:name}_test() {
-    ${0}
-  }
+	pub fn ${1:name}_test() {
+	  ${0}
+	}
 
 snippet af "anonymous fn"
-  fn(${1}) { ${0:${VISUAL}} }
+	fn(${1}) { ${0:${VISUAL}} }
 
 snippet let "let binding"
-  let ${1} = ${0}
+	let ${1} = ${0}
 
 snippet l "let binding"
-  let ${1} = ${0}
+	let ${1} = ${0}
 
 snippet as "assert binding"
-  assert ${1} = ${0}
+	assert ${1} = ${0}
 
 snippet tr "try binding"
-  try ${1} = ${0}
+	try ${1} = ${0}
 
 snippet - "->"
-  -> ${0}
+	-> ${0}
 
 snippet case "case expression"
-  case ${1} {
-    ${2} -> ${0}
-  }
+	case ${1} {
+	  ${2} -> ${0}
+	}
 
 snippet ty "type"
-  type ${1:Name} {
-    ${0:$1}
-  }
+	type ${1:Name} {
+	  ${0:$1}
+	}
 
 snippet pty "pub type"
-  pub type ${1:Name} {
-    ${0:$1}
-  }
+	pub type ${1:Name} {
+	  ${0:$1}
+	}
 
 snippet tya "type alias"
-  type ${1:Name} =
-    ${0:$1}
+	type ${1:Name} =
+	  ${0:$1}
 
 snippet ptya "pub type alias"
-  pub type ${1:Name} =
-    ${0:$1}
+	pub type ${1:Name} =
+	  ${0:$1}
 
 snippet ext "external type"
-  external type ${0}
+	external type ${0}
 
 snippet pext "pub external type"
-  pub external type ${0}
+	pub external type ${0}
 
 snippet exfn "external fn"
-  external fn ${1:function_name}(${2}) -> ${3}
-    = "${4}" "${0}"
+	external fn ${1:function_name}(${2}) -> ${3}
+	  = "${4}" "${0}"
 
 snippet pexfn "pub external fn"
-  pub external fn ${1:function_name}(${2}) -> ${3}
-    = "${4}" "${0}"
+	pub external fn ${1:function_name}(${2}) -> ${3}
+	  = "${4}" "${0}"
 
 snippet im "import"
-  import ${0:gleam/result}
+	import ${0:gleam/result}
 
 snippet im. "import exposing"
-  import ${1:gleam/result}.{${0}}
+	import ${1:gleam/result}.{${0}}
 
 snippet p "|>"
-  |> ${0}
+	|> ${0}
 
 snippet tup "tuple()"
-  tuple(${0:${VISUAL}})
+	tuple(${0:${VISUAL}})
 
 snippet bl "block"
-  {
-    ${0:${VISUAL}}
-  }
+	{
+	  ${0:${VISUAL}}
+	}
 
 snippet tf "fn(Type) -> Type"
-  fn(${1}) -> ${0}
+	fn(${1}) -> ${0}
 
 snippet seq "should.equal"
-  should.equal(${0:${VISUAL}})
+	should.equal(${0:${VISUAL}})
 
 snippet strue "should.be_true"
-  should.be_true(${0:${VISUAL}})
+	should.be_true(${0:${VISUAL}})
 
 snippet sfalse "should.be_false"
-  should.be_true(${0:${VISUAL}})
+	should.be_true(${0:${VISUAL}})